computer applications technology mind...
TRANSCRIPT
Revision date: 26 October 2018
COMPUTER
APPLICATIONS
TECHNOLOGY
MIND MAPS
The information in these mind maps is supposed to supplement the textbooks, not
replace it.
Although the author has made every effort to ensure that the information is correct,
the CAPS document must still be consulted as the primary guideline.
Please report any omissions or errors to [email protected]
Compiled by: Claire Smuts
Translated & checked by: Fotiene Avrakotos
QR codes to videos: Fotiene Avrakotos
2
Information
Processing
Cycle
Input
•give input to the
computer. Without it,
the computer does
not know what to do
Processing
•the interal process
where the computer
processes data so that
what you requisted
can happen (e.g.
sorting, searching for
something on the
computer)
Output
•what the computer
gives back to you
after the processing.
Normally 'soft' output
on the screen or 'hard'
output on printout
Storage
•to store the output
permanently, you
store it on a hard
drive or a flash disk
Communication
•many times you share
the output you saved
with other people
through e-mail etc.
ICT: Information and Communication Technology
ICT refers to technologies that provide access to information through telecommunications (such as the
Internet, wireless networks, mobile phones and other communication media)
3
Inp
ut
devic
es
Keyboard
(wired &
wireless/
bluetooth)
Physical keyboard
Touch screen's pop-up
keyboard
Disabilities
For blind people - braille
keyboards, microphone
For visually impaired/motor skills
- keyboard with big buttons
Pointing
devices
Mouse (wired & wireless)
Wireless advantages: Cables are
not in the way, can work far from
computer
disadvantages: theft risk, needs
batteries, more expensive to buy,
interference of signals, weaker
response time (also applicable to
keyboard)Touch pad
Pointing stick
Stylus
Graphics tablet/drawing
tablet/digitizer
Almost like a huge touch pad -
for artists
Touch screen/multi touch
screen
Can recognise more than one
'touch' and react - like
pinch/zoom (also applicable to
touch pad). For security, use a
screen lock pattern on portable
devices.For motor disabilities -
trackball/footpedal/
suction-blowing device
Gaming devicesJoystick, Steering wheel,
Controller (Xbox/Playstation)
Scanners
(resolution
measured in
dpi)
Barcodes (uses light light
rays/ optics)
Represents numbers/words that
can be looked up in a database.
Used in POS system (point of
sale) - for improved accuracy and
speed (ensure that you can
describe the flow)RFID - wireless (uses radio
waves)
Cellphone camera reads
QR codes
Quick link to weblink - does not
need to type in URL manually
Card readers (bank card) -
OTM / paypoint
Biometric - Face recognition
with camera, Fingerprint,
Iris/Retina scanner
For security - much better than
password, cannot forget it
Linked to one person's unique
biometric features
Disadvantage - you have to be
there in person, can endanger
you
Office Flatbed (1 at a time) &
Feeder (pack of paper)
scanner
Character recognitionOCR - software that converts it to
editable text
Video & sound
Webcam (communication /
eye tracking), Digital video
camera
Microphone (voice
recognition, record music)
HARDWARE
(Peripheral)
4
Pro
cess
ing
co
mp
on
en
ts(in
sid
e y
ou
r sy
stem
un
it)
Motherboard
Circuit board that connects all components and parts of the
computer with each other
Contains a couple of slots for additional cards like sound and
graphics cards
*CPU - does the
processing/thinking
Speed measured in = GHz
Quad core = 4 cores (processing units)
>1 important for multiprocessing (excecuting multiple
programs simultaneously)
Cache memory - files are kept in super quick memory so that
access to the CPU is faster (than to RAM)
Well-known brands e.g. Intel / AMD
*RAM
(Primary Memory)
Function: loads current programs & documents when it is
processed by the CPU so more RAM = can run more programs
simultaneously
Feature: unstable/volatile: in other words: loses content
withouth power (temporary)
E.g. DIMMS, DDR3/DDR4
Measured in GB
Cheapest way to upgrade computer & improve performance
ROM
(Read only memory)
Small chip built-in on the motherboard
Helps computer 'boot' - startup process (e.g. tests if all
components needed is there)
Software on ROM that contains basic instructions:
BIOS - Basic Input Output System
Graphics card
Onboard = built-in on motherboard,
Dedicated = separate card (better graphics)
Has its own RAM and GPU (Graphics processing unit) thus
better performance since the system CPU & RAM is not used
by graphics
Well-known brands e.g. NVIDIA GeForce, AMD Radeon,
Gigabyte
PSU - Power supply unitSupplies appropriate voltage to
computer system
Heat sink - to keep electronics cool
HARDWARE
(components)
* Biggest
influence on
performance/
speed of
computer
5
Ou
tpu
t d
evic
es
Screen (soft copy - thus
electronic on screen)Specifications
Size measured in inch" diagonal over screen
Resolution measured in pixels
e.g. 1920 x 1080 (also 720p, 1080p, 2K, 4K)
Aspect ratio e.g. 4:3, 16:9 (ultra-wide e.g. 21:9)
relationship of length versus width
Response time e.g. 2ms (milliseconds)
how quickly a pixel can change from one shade to another
Refresh rate e.g. 60Hz (standard) 144Hz (gamer)
how many times the screen is 'redrawn' in 1 sec
Contrast ratio e.g. 1:1000000, number of variations between
light and dark (lower ratio - faded image)
Colour depth e.g. 8-bit, 32-bit
Number of colours that a screen can display
e.g. 24-bit=16.7 million colours
Viewing angle - from how far left/right/above/below you can
see the image on the screen clearly
Nowadays you get curved screens that gives a better
experience for large and very wide screens - also better for
posture (ergonomics)
Use VGA (old), DVI (upgrade
of VGA), HDMI or
DisplayPort (new) cables
HDMI & DisplayPort for
high resolution and can also
transfer sound
Need an adapter or convertor if your computer doesn't have
the same ports as your screen
ProjectorMeasures brightness in
lumens (needs expensive
bulb with limited hours)
Interactive whiteboard
Using a projector, an
instructor can manipulate
elements on the board
using finger/special pen as a
mouse, directly on screen
Fax
For people who are deaf-
devices that vibrate
Audio output
Audio output is important
for people who are blind
Speakers & headphones: to
share sound output with a
larger audience
Problem solving
Sound too soft: if a speaker is USB-powered, the sound will be
much softer than the general AC power. May need an
amplifyer for much louder sound.
No sound from computer speakers: ensure the speakers are
plugged in at the power outlet and in the computer itself.
Computer sound should be on (not on mute or soft) and the
correct sound output device should be chosen in the menu.
Sound card drivers need to be installed.
Poor quality sound: quality of the device needs to be good,
speaker can be damaged, file itself can be compressed =
leaading to low quality sound
Bluetooth speakers/earphones: Unpair and pair again - check
that it's charged - Note: Bluetooth uses more power on a
device than a regular cable
Earphones/headphones:
private, doesn't bother
other people, can have a
built in microphone as
well - for e.g. cellphone
calls or gaming (then called
a headset)
Specifications (per
connection type)
Cabled
Aux (3.5mm)
USB/Mini-USB/USB-C
Always better sound - no connection
problems
Wireles
NFC, Bluetooth, need WiFi for
internet stream services
Advantages: more mobile (take it
anywhere)
Disadvantages: requires batteries/to
be charged, signal/connection
problems
HARDWARE
(Peripheral)
6
Ou
tpu
t d
evic
es
Printer (hard copy -
printed page)
Specifications
Speed: ppm - pages per minute
Resolution: dots per inch (dpi)
Workload/duty cycle: how many pages it can print in a
month/lifetime
Number of ink colour containers (e.g. CMYK - Cyan,
Magenta, Yellow, BlacK) - important so that you can
replace 1 at a time
Paper options: size e.g. A2 (NB: A0 largest, A10 smallest)
weight gsm - i.e. thickness
Tray capacity = e.g. 100 / 500 sheets of paper
Connection options e.g. WiFi, NFC
General
Default printer (indicated with ) - print to it
automatically
Printing queue - where the print jobs wait in line
Spooling - the process of sending print jobs to the queue
& the printer
Problem solving
(possible faults)
Sent to the wrong printer (e.g. replaced default printer)
Is printer on and connected to the computer?
Is there enough ink and paper?
Can possibly have the wrong paper size in the printer tray
or a jammed paper
Fault can lie in the printer queue - print tasks that were
stopped or paused
Laser (commonly used
in businesses)
Printer itself is expensive
Print 'powder' is fused onto the paper with heat
Toner is expensive but cost per page works out cheaper
Quick printing speed
Multifunction (print,
scan, copy, fax, email)
Advantage: saves cost & space because all the devices are
in one. Disadvantage: if 1 breaks and is sent in for repairs,
all the other functions are not available
Inkjet (mostly home
use)
Printer itself is cheap
Liquid ink is placed onto paper
Ink is relatively cheap but cost per page is expensive
Slow printing speed
New type: inktank printer - now works out much cheaper
than traditional inkjet printers
Dotmatrix
(e.g. pharmacists)
Prints duplicates
Low resolution quality - low cost
3D printerPrints 3 dimensional solid objects from a digital 3D model
by adding successive layers of material on top of one
another.
Braille printer (for
people who are blind)
HARDWARE
(Peripheral)
7
Sto
rag
e d
evic
es
Memory cards for
extra storage space in
e.g. smartphone or
digital cameras
(needs card reader for
copying to computer)
Micro SD, Mini SD, SD,
CF, MMC
Optical media CD, DVD, Blu-Ray
Advantages: cheap
storage media (ideal for
archiving), read-only
Disadvantages:
Damages easily, slow
read/write speed,
cannot store a lot of
data (small capacity)
Copying contents off a
protected disc is
referred to as "ripping"
a disc
USB Hub for
additional USB ports
Micro-USB's are used
for e.g. smartphones
Flash disks
(electronical - flash
memory)
Ideal for portable
storage - larger capacity
than CD/DVD, fast
read/write speed, does
not damage easily,
physical size is small
Hard drives
(secondary storage)
Types
SSD (Solid state drive)
(Flash memory)
Advantages: Faster data
access, does not
damage easily (no
movable parts),
generates less heat.
Commonly used to load
operating system to
increase performance of
computer
Disadvantage: Much
more expensive per GB
than HDD, not good for
long term storage (loses
charge), limited write
cycles
HDD (Hard disk drive)
Kinds
2.5" Portable (USB
powered)
3.5" External (simple
power plug in)
Internal(usually connects with
SATA cabels)
Features
Function: Permanent
storage of programs &
data
Characteristic: Stable/non-
volatile: keeps contents
without power
Slower read/write speed
than RAM
Can connect multiple
HDD's through a RAID
system
Serves as virtual memory
Area on hard drive that
servers as RAM (when RAM
becomes full). Swop files
are files that swop between
the HDD & RAM. Thrashing
is when the HDD is
overloaded by the fast
exchange of files between
system memory (RAM) and
virtual memory (on the
HDD)
Measurements of
storage devices
1 KB = 1024 bytes
1 MB = 1024 KB
1 GB = 1024 MB
1 TB = 1024 GB
1 PB (Petabyte) = 1024 TB
HARDWARE
Capacity: the
maximum
amount that
something
can contain
8
Typ
es
of
Mu
lti-
pu
rpo
se D
evic
es
Portable
(BYOD policy)(bring your own
device)
Ultrabook
Usually contains SSD
Very high screen resolution
No optical (DVD) drive
Thin & light = expensive!Laptop/Notebook
Tablet-PC /
Hybrid / 2-in-1
Laptop and tablet in one (screen can be taken
off)
Netbook (cheapest type of laptop)
Small screen (<13")
Minimum specs (slow)
No optical drive
Tablet Not all types can make calls
PhabletScreen size between tablet & smartphone, can
make calls
SmartphoneHas GPS, camera (that can be used as scanner),
gyroscope, accelerometer
Not portable
Desktop PC
Entry level - basic computer with low specs
High-end - top specs
Also get an all-in-one where the system unit is
built into the screen
Server (in network)
Work station (very
strong computer)Used by e.g. scientists / architects / video
editors
Mainframe computerSuper size server - spans many rooms - MAIN computer
in big organisation - focus on processing LOTS of data
Super computerPushes the limits what is possible for computers, most
powerful - focus on processing as FAST as possible
Ded
icate
d d
evic
es
Only 1 purpose
GPS (can also be built
into smartphone/car)
Definition: measures physical location with
geographical coordinates with satellites
GPS regularly updated
Can plan routes automatically
Can share your location with others
Can keep your eyes on the road more than you could
with a printed map
ATM (handles
financial tasks)
Digital cameras
Resolution measured in
Megapixels (MP)
Note: Mega = million
The higher, the better,
but takes more space
ISO rating - light
sensitivity
Zoom
Optical - better quality -
done with lenses
Digital - done with
softwareSensor size - larger =
better quality (e.g. DSLR)
GeotaggingPlaces GPS coordinates
in photo's metadata
HARDWARE
Keep
co
mp
ute
rs s
afe
:
•Lo
ck r
oom
/off
ice
•U
se c
able
lock
•A
ctiv
ate
ala
rm /
move
men
t
sen
sor
Pro
tect
desk
top c
om
pu
ters
again
st
pow
er
failu
res
an
d p
ow
er
peaks
wit
h a
UP
S –
un
inte
rru
pta
ble
pow
er
supply
9
Co
ncep
tsErgonomics
The design of devices /
items to fit to humans
natural form
E.g. Chair with good backrest / table with
right height
RSI - repetitive strain
injury
Get different types e.g.
Carpal Tunnel Syndrome
(wrists) or Gamers thumb
Suggestions to prevent:
Use ergonomically designed INPUT devices
Take regular breaks
Green computing
Definition: Environmentally
friendly use of computers
Rather fix/ reuse any
devices
Switch off when not in use
or sleep/hibernate
Discard responsibly - with
supplier
Save paperPrint 2 per page, back to front, check print
preview, distribute electronically
Save ink Draft/Eco mode (lighter), less pictures
ConvergenceCombining multiple devices
/ technologies into one
device
E.g. Smartphone/Tablet/
Smart TV/Multifunction printer
Ethical use
(right & wrong)
No piracy, respect privacy, no malware
Digital divide is when people don't have access to technology due to a
lack in skill/knowledge or finances
Types of users
Personal userSomeone who uses computers for personal
reasons (minimal for work)
SOHO - Small Office Home
OfficeBusiness managed from a house
Mobile userAnyone using computer devices "on-the-go"
thus anyone who owns a smartphone
Enterprise userAn enterprise) is a company which hundreds
or thousands of employees - each user in
such company is an enterprise user
Reasons for using ICT
More Effective, Accurate &
Reliable than people
More work in less time, do not make
mistakes, do not get tired, doesn't strike
Communication is so much
easier & faster
Always give examples in comparison with
mail / letters
Economical Save paper, labour, communication costs etc.
HA
RD
WA
RE
10
New
Teg
no
log
ies
Virtual Reality
DefinitionUsing technology to create a simulation of a
3D-environment that can be interacted with a
person in a seemingly real or physical way.
How it works & Purpose
Using equipment such as helmets with screens
and gloves fitted with sensors, it allows users
to be immersed into a virtual world. E.g.
Google Cardboard, Oculus Rift, HTC Vive etc.
Uses
Explores places such as travel destinations
(using 360° videos).
Virtual reality makes education more engaging
and entertaining.
Used to train employees (example pilots being
trained) without causing damage or risking
lives.
Limitations
Technology is still new so there are technical
limitations such as weak hardware and low
resolution.
Moral and ethical concerns
Artificial Reality
DefinitionIt takes the physical world and adds
(augments) objects such as graphics within the
real world.
How it works & Purpose
Simplest versions use smartphone camers, but
there are technologies such as Microsoft
Hololens that contain software, sensors, a
compass and small digital projectors which
display images onto real world objects.
To enhance our real world for purposes such
as entertainement (e.g. Pokemon Go,
SnapChat filters) or productivity (e.g. Heathrow
Airport Guide that helps you get to the right
gate)
Uses
Entertainment and education applications
include cultural apps with sightseeing and
museum guidance, gaming apps with
traditional games using AR interfaces, and
some smartphone apps that make use of AR
for an entertainment and/or educational
purpose.
AR can be applied so that the surgical team
can see the imaging data in real time while the
procedure is in progress.
Limitations
Due to the fact that the content is not real, it
may obscure or narrow a user's interests or
tastes
There are also privacy concerns. Image-
recognition software coupled with AR will,
quite soon, allow us to point our phones at
people, even strangers, and instantly see
information from their Facebook, Twitter,
Amazon, LinkedIn or other online profiles.
HARDWARE & SOFTWARE
11
Syst
em
So
ftw
are
Operating system also
referred to as 'platform'
Graphic user interface
(graphical way for people
to interact with the
computer)
Menus, Icons, drop down lists
E.g. Windows 10 (paid)
E.g. Linux (OSS)
E.g. Android (smartphone)
Functions
Control basic security (logins)
File management (folders, file extensions etc.)
Manage integration between software and hardware
Drivers for devices (manage communication between
device & OS - lets device be controlled)
When devices are automatically installed, it is "Plug and
Play"
Utilities
when it does not come
with the operating
system, it is a
third-party utility
Backup Good habits - not in the same place, safe place etc.
Uninstaller Used to remove programs safely from computer
Compression (.zip / .rar)Like Winzip - makes it smaller & can then email folder.
Can zip or unzip to use again (to edit)
Defragmenter
Adds pieces of files that are spread over the whole HDD
together again to improve SPEED
Can slow down computer speed (performance) while
scanning
Disc Cleanup WizardSearch your computer for cached / temporary files or
programs that you no longer use / recycle bin that is full
and gives you the option to delete / remove.
Disc Scanner Scan & fix flash- and Hard drives
FormatPrepares the drive for storing files. Often used in case of
corruption/virus contamination because it wipes the
content of the storage medium.
Antivirus
Update, update, update
virus definitions so that it
can be recognised!
Examples: Kaspersky, McAfee, Norton EsetNOD32.
Free: Windows Defender, AVG Free Edition
Scan internal / external
harddrives / flashsticks for
viruses
Can slow down computer speed (performance) while
scanning
Put potentially harmful /
malicious software in
quarantine
Quarantine: Safe area on hard drive where virus cannot
harm anything - allows you to choose or remove
something
SOFTWARE
System software manages
resources on computer / allows
computer to be used
Application software are
programs for personal use /
tasks
12
Ap
pli
cati
on
So
ftw
are
Graphics & Design Photoshop, Paint Jpeg, bmp, png
Office Suite
Word, Excel, Access, Powerpoint
.docx, .xlsx, .accdx, .pptx
Share document with formatting =
.rtf, without formatting = .txt, in
table format = .csv (comma
separated values)
.PDF (E.g. Adobe Reader - free)
Other people cannot easily change
content
Can open even if you do not have
the original software
(retains formatting)Communication Outlook, Skype, WhatsApp
Games
Entertainment Windows Media player, VLC
Sound (.mp3, .flac, .wav)
Videos (.mpg, .mp4, .avi, .wmv,
.mov)
Webbrowser
(files .html)
Chrome, Firefox, Internet
Explorer, Microsoft Edge, Safari
Plug-in!
(needed for multimedia)Flash, Quicktime, Java
Typ
es
FreewareFree, may share and use freely
e.g. Adobe Reader
Shareware (trial software
also falls under this)
Can be used free for a while
(test period), then pay or lose
(some or all) functionality
Free and Open Source
Software (FOSS)
Like freeware, but can change
source code and program
further
E.g. Linux, Android, Open Office,
Ubuntu
Advantage: Many people can work
on code
Proprietary (paid)
License Agreement (EULA) (also
for free, share & OSS)
EULA: End-user license agreement
Single user
Site License (many computers on
one site for one company)
Piracy (software piracy)When software/anything is shared
illegally. Fight through: serial key /
online activation
SO
FT
WA
RE
Examples of file extensions
Remember metadata?
Information about a file
– e.g. author, editing
time, type of camera,
music genre etc.
Purpose of file extension:
defines type of file & helps
OS associate it with a
specific program
13
Co
ncep
ts
Updates
Try to prevent bugsReleases a test version namely
'Beta' version
Necessary due to software
error / bug or just for
improvements
Specific problem made in
software when created
Bugs can be security gaps
which gives hackers a 'way in'
PatchSoftware solution for one
specific problem
Service PackCollection of all previous
patches & new features
If a program does not respond
/ hangs
Press CTRL+ALT+DEL / Open
Task Manager"End task" - Ends the program
CompatibilityA problem between different
versions of the same software
'Backwards compatibility' -
New program can open old
files, old program can not
open new files
Solve problem by upgrading
all (newest version), to
standardize (same version) or
to export file to older version
System compatibility - is the
computer hardware sufficient
for the software
Minimum specificationsJust enough so that program
can install and work
Recommended specs
Enough so that program
works fully (excellent), smooth
output
Software Accessibility options
(For people with
disabilities/disabled))
Text-to-speech
(speech synthesis)
Computer reads to you what is
on the screen
(requires speakers - output)
Speech-to-text
Computer can respond / type
your voice commands
(requires microphone - input)
Magnification
High contrast theme
Black background with white
text for people who are
struggling to see
Sticky KeysHelp people to press shortcuts
etc. 1 button at a time
File management
Folders within folders in
logical order
File path e.g. C:\My
Documents
Step-by-step indication in
which folders a file is stored
SOFTWARE
14
Featu
res
Advantages
Can share resources like printers and Internet access
Data is kept in 1 central location / central storage
Easy communication between users
Share of software and / or updates
Can make backups from 1 central location
Can set user permissions such as access to specific folders or disable USB
drives to prevent theft of data and malware spreading
Disadvantages
Viruses spread easily
Must have a lot of knowledge to draw up
Requires good security (so unauthorised users can not access confidential
information)
Co
ncep
ts
In school/work environment
an AUP is signed
Acceptable use policy
Definition: Contract / agreement between user and institution
Includes what may and may not be done on the network, forms of online
communication allowed, amount of data that may be used, use of flash sticks,
procedures for problems like identity theft, viruses etc., tips to prevent
copyright infringement and plagiarism.
Virtual Private Network (VPN)
A virtual private network (VPN) is a technology that creates a safe and
encrypted connection over a less secure network, such as the Internet
The benefit of using a secure VPN is it ensures the appropriate level of security
to the connected systems when the underlying network infrastructure alone
cannot provide it
Typ
es
PAN - Personal area network -
can fit on 1 table
HAN - Home area network -
2 or more rooms
LAN - Local area network -
more computers in 1 roomWLAN - Wireless LAN
Additional advantages:
Easily add more computers/devices
Faster to set up because there is no
need to lay cables
Better portability of devices
(no cables)
Additional disadvantages:
Security risk is extra high for hackers
Can use up internet data if others
gain access
Signals can be disrupted
Can be slower than cabled network
due to obstructions like walls
WAN - Wide area network -
E.g. Gauteng
GAN - Global area network -
e.g. Internet world wide
NETWORKS
15
Hard
ware
Need
ed
Server: Provides services/resources
to computers in the network
such as printers & Internet.
Special server operating system
(e.g. Windows Server 2016)
File server
Proxy server (internet server)
Controls which sites may be
visited
Can monitor usage of
individual people
Does central web storage
(web caching) and save dataE-mail server
Print serverControls all the printers in
the organisation
Workstation/Client: Uses the
services/resources provided by the server
- therefore not as powerful
Thin client
Must connect to network to
work - basically just a screen,
keyboard & mouse
Fat clientCan function as standalone
computer
Must have a NIC in computer
to connect to network
Network Interface
Card/Controller
To connect 1 device to a
network, note: you also get a
wireless NIC
*Switch: A device that connect devices on
the network (internally - many devices to
each other)
*Modem: Convert digital signals from
your devices to signals that
can be sent over your Internet
connection and vice versa
Cables - UTP (common network cable -
cheaper) - uses RJ45 port or FIRE OPTIC
(use light beam = fast data transfer)
General advantages of cables
above Wi-Fi
Better because it's more
stable & faster signal
Less knowledge needed to
set up vs. wireless network
Better security (people do
not hack into it so easily)
Fibre obtic usually used as
'backbone'
'Backbone' = connects two
LANs to each other
Note: Fibre is very expensive,
requires training to install &
breaks very easily
*Router: Connect a network to another
one - eg. your home to the Internet
Dongle: Looks like a flash disk in which a
SIM card can be inserted to use cellular
Internet on a computer/laptop
Can "tether" your phone also
use like a USB Dongle
Also get a Mobile Wi-Fi
Router - does not connect by
USB (for charging only). Also
known as pocket Wi-Fi*Wi-Fi access point: A network device
that allows a Wi-Fi device to connect to
a wired network
Wi-Fi Repeater: Used to extend the
coverage area of your WiFi network. It
receives your existing WiFi signal,
amplifies it and then transmits the
boosted signal.
*Firewall: Hardware/system software
that monitors access/ control from the
network/devices to and from another
network (like the Internet)
NETWORKS
* In a standard home Router, these
five devices/features are merged
16
Inte
rnet Services:
VoIP = Voice over Internet
Protocol e.g. Skype
Cheaper than regular calls (only uses
data)
Can send video & audio
Can make calls wherever Internet access
is available
Available on different devices like
computers & smartphones
Video usage can use a lot of data
(especially with a high resolution
webcam)
Instant messaging (WhatsApp,
Facebook Messenger,
Hangouts, Skype chat)
Fax to email
Grid computing: Using multiple
computers' processing
power to solve 1 problem
(as if it were 1) e.g. SETI
FTP = File transfer protocol -
share of large files over a long
distance through the Internet
Cloud computing
(web applications)
Use of programs through a web browser
- runs and is installed on Internet servers
instead of on own computer
Saas - Software as a Service - where you
pay a monthly/annual fee and receive
the software as a service on the web
No installation/updates required
Your own computer does not have to be
so powerful because it works from the
Internet server
A lot of people can easily work together
on a document
Disadvantages: Internet access required,
programs usually contain less features
versus "desktop version", many types
are SaaS (need to pay) only some free
Cloud storage
Storing information/files on Internet
servers
Can get information anywhere if you
have Internet access
Can serve as a "Backup" for your data
Synchronises devices with the same
content
Disadvantages: requires internet
connection for access to data, you only
get a small amount of space for free
(need to pay after that), up and
downloading data costs money, no
control over backup and security
Netiquette = Good manners
on the Internet
Do not type in capital letters
(shout)
Good spelling
Do not send large email
attachments
INTERNET
The INTERNET is a global network
of computers
The WWW is only one of the
services on the Internet that
displays web pages
INTERNET is a global network that is
publicly available
INTRANET is shared content that is
only accessible to members of a single
organisation.
EXTRANET is a private network that
uses Internet technology and the
public telecommunication system to
securely share part of a business's
information or operations with
suppliers, vendors, partners,
customers, or other businesses. An
extranet can be viewed as part of a
company's intranet that is extended to
users outside the company.
17
Inte
rnet
Serv
ices
To: to whom the e-mail is addressed
CC: other people who are being copied to take note - everyone can see each other's email
addresses
BCC: people who are copied but cannot see each other's addresses (Netiquette - BCC people
when emailing a group)
RE: an email reply automatically gets this prefix in front of the subject
FW: an email sent to someone else automatically gets this in front
of the subject
Subject line: the subject of the email
Reply to all: when there is more than 1 person in the To or CC field
you can "reply to all" and send a message to the same big audience
(use with consideration!)
Attachment: attach a file to email
(size limited to a certain number of MB)
Mail rule: automatic actions in an e-mail program
according to rules you specify
Flags/Tasks: you can add emails (or your own items) to a task list in the email software,
specifying due date and even set reminders
Registration
Registrations for new sites / services are usually done with an email address or Social network
account. A CAPTCHA is then also asked to verify that it is a human attempting the registration,
and not a computer (which would probably be a DDoS attack).
Social
networks
Definition: Online service or technology that allows people with similar interests to
communicate with each other regardless of time or distance
E.g. Facebook, Twitter, Instagram. Often use a URL-shortener service to shorten URL's before
posting to social media (no problems with character limitations and just looks neater)
Benefits: Allow groups to create virtual communities or pages for businesses/famous people,
etc.
Huge audiences to share your life with
Can inform family members/friends about your life
Businesses can place cheap and targeted ads and
interact with their customers
Disadvantages: Thinking that friends on social media are real friends
Danger of Cyber stalking/Cyberbullying
Danger of online predator/pedophiles
Someone who does not know you, may monitor your online habits to take advantage of it (to
your detriment)
May be addicted to social networks
Protect yourself/your business:
Do not publish offensive content
Do not accept friend requests if you do not know the person
PodcastAudio file downloaded from the Internet that can be played on computers or devices such as
smartphones e.g. with radio programs/training etc. (Vodcast - when it includes video)
WebcastOne-way flow of information broadcasted over the Internet to a large audience that may consist
of audio, video and/or presentation slides
Audience does not usually contribute to content
WebinarInteractive meeting or seminar. The content is usually education-based. The audience is usually
smaller and takes part in the conversation through surveys, Q & A etc.
INTERNET
18
Wo
rld
Wid
e W
eb
Web address = URLwww.[websitename].
[organisation].[location]
E.g. www.hsrandburg.co.za
Types
Portal - access point to
many at www
Services e.g. e-banking,
e-commerce
Encripted connection is
indicated with https - don't do
transactions on public
computers
Research seller's reputation
looking at gradings and
reviews before first purchase
Advantages: available any time
of day from the comfort of
your own home, can do better
comparisons (price, variety
etc.)
Disadvantages: can fall victim
to scams if user doesn't do
sufficient research
Online transactions are verified
using a OTP (one-time
password) on your cell
Wiki - website where
people work TOGETHER to
create/compile it
Content aggregator: Gather
information from many
websites - like RSS feeds
Crowd funding platform (website): a process where a single idea
or business practice is funded by multiple small donations from
volunteer contributors, usually before the business venture is
started. The contributors will then receive the product when it is
finally put into production
Blog (like a online diary,
chronological)
(Vlog = video blog)
Good blog habits: Update
regularly, use pictures/videos,
respond to readers'
comments. Create using
Wordpress, Tumblr etc.
Program = web browser,
eg. Chrome, Firefox.
The program/application
used to visit/view web
pages
Features
Home button (page on which
your browser opens
or you can go back to)
Back / Forward
Favourite / Bookmark - save
the link to the website for
future use
History - return to
chronological history of
previously visited addresses
Address bar - where the URL
of the website shows (also
search bar)
Tabbed browsing - so that
many web pages can be open
at once
Browser plug ins: To see
multimedia e.g. Flash Player,
Quicktime.
Use Search engine = e.g.
Google, Bing, Yahoo!
Software that allows a user
to search for information on
the www using keywords
(like a library assistant)
Webcaching =
Webpages that have
previously been visited are
stored on the "local pc" (faster
access in future & saves data)
INTERNET
Effective searching on WWW:
Add more key words
Use advanced search
like -word to exclude terms
Use filters e.g. when it was
posted / type of source
(news/ image etc.)
19
New
Tre
nd
s
Big data
DefinitionVery large structured (clean data) and unstructured (e.g. free text
tweets/reviews) data sets that are analysed using computers to reveal trends.
Purpose Reveals patterns and trends relating to human behaviour and interactions
UsesTo optimize and improve lives. E.g. shopping habits, health risks and indicators
of serious illnessess.
Limitations
Massive skill shortage on interpreting big data.
Required hardware and software is extremely expensive.
Shortage of space to store all the data
Privacy concerns
Internet
of
Things
Definition
The trend whereby all sorts of objects and devices are increasingly being
connected to one another via the Internet, communicating independent of
human interaction.
PurposeSensors in devices produce data (see big data) that can be used for diagnostics
and running systems more efficiently.
Uses
Devices can communicate without human intervention to automate and
improve processes and reporting, e.g. heartrate monitor in smartwatch triggers
alarm when your sleep cycle is at its lightest
Limitations
Internet connection required
Privacy concerns about data being gathered about your behaviour
Bitcoin
DefinitionA form of virtual, digital currency. Most well-known example of a
cryptocurrency.
PurposeSend money anywhere in the world at any time - no limits. Decentralised from
banks and governments so no interference and minimal 'bank' charges.
Uses
Bitcoins can be exchanged for other currencies, products, and services. They
have caused concern in that they are often used for payment in criminal
activities such as ransomware demands. However, more and more legitimate
companies are accepting them as a means of payment.
LimitationsNot very widely accepted yet. Bitcoin wallets can be lost. Currency is extremely
volatile.
Digital migration
A process in which broadcasting services using traditional analogue
technology are replaced with digital technology. This provides better quality
pictures and sound as well as electronic programming guide. However, there
will be more costs for the user.
Mobile or M-learning
A form of education and training delivered and conducted via the Internet
using mobile devices, such as tablets and smartphones. It is designed to be
flexible, allowing learners/workers/students access to education anywhere,
anytime.
INTERNET
20
Wo
rld
Wid
e W
eb
Usability of websites
- basic principles
Readability
Use headings, short paragraphs,
columns
Bullets / numbered lists works well
Group information that belongs
together logically
Background should be easy on the
eyes (not too bright)
Use standard capital and lowercase
letters - ALL CAPS is difficult to read
Fonttype, size and colour should be
readable
Navigation
Links should be easy to find,
especially main menu
(home/contact us etc.)
Links should be short and
understandable
All hyperlinks should work
Links should all look the same
Consistency (the same everywhere)
Same basic layout for all webpages
in the website
Use the same colour / font types /
theme
LayoutHow different elements
are placed
Has to be suitable for target market
(website for young kids would look
different than one for teenagers)
Text and graphics should fit on a
standard screen
Websites should load quickly (not
too much multimedia)
TypographyThe placement and
formatting of text
Needs to be easy to read
Needs to match content (can't use a
funny font for serious content)
Use general font types so that it's
available on all computers
Not to many font types on one
website
Mobile websitesWebsites specifically
designed for
smartphones/tablets
INTERNET
21
Tech
no
log
ies
Cellular (any connection
using a SIM card)
Can it use it anywhere
3G (older)
4G / LTE (newer - faster)
ADSL - transmits
electricity via copper
cables
Fixed connection at home
Cheaper than cellular only if data usage is high
More stable connection than cellular (using copper telephone line)
Asymetrical = Download speed high, upload speed slower
Fibre - transmits light
via fibre optic glass
cables
Highest (possible) data transfer speed (depends on ISP package)
Strongest signal (little interference)
Low latency - can travel far without signal degrading
Not easily damaged by lightning, however very fragile (glass)
Sp
ecif
icati
on
s
ISP - internet service
provider = connect you to
Internet (e.g. Mweb /
Vodacom)
Every ISP has an AUP (Acceptable Usage
Policy) / FUP (Fair Usage Policy)
How much data you may use (even
though you are uncapped) without
them throttling you
BandwidthThe amount of data that can be sent/received in a certain time. Upload (data sent) vs
download (data is received) speeds often differ
Capped / uncapped
dataAmount of data that you can upload and download in a specific period (ADSL & Fibre =
monthly packages)
Shaped / unshaped
Companies can prioritise which services can get full speed according to their own needs
Home use (ISP) Full speed all day: (low data
usage services)E-mail, regular browsing
Low speed by day (services that have high data
usage), usually full speed night hours e.g.:
"Streaming" video (video that will
never be stored on your computer)
Gaming / Torrents / VoIP
ThrottlingUse so much data that they drastically lower
your overall
speed (penalty)
Type of connections
Cabled (ADSL/Fibre)
Wifi (802.11) - Wireless technology
Letter after 802.11 refers to speed
e.g. b/g/n
Can use any of the technologies
listed above
Affected by walls /
blockages
WiFi hotspot - area with
WiFi coverage
WiMAX - tower that broadcast Wi-
Fi to a large area (few kms)
Bluetooth - short distances -
pair devices
NFC - near field communication like file
transfer between mobile phones / payments
with NFC bank cards - just tap
BROADBAND =
High speed data transfer
INTERNET
22
Safe
usa
ge
Features of secure
websites
URL starts with https (means connection is encrypted)
Address bar turns green
Lock icon shows
Critical to update
your antivirus,
operating system
& browser
Be aware of:
Unexpected pop-ups (don't click on it)
Unknown attachments / programs
Spam: unwanted or intrusive advertising on the Internet
Hoax: something distributed with the intention to deceive - usually false, sometimes
ridiculous information/stories (fake news)
Scam: a misleading, dishonest offer/action e.g. a false online shop that steals your
money and doesn't send you the product
Phishing: a scam where an Internet user is tricked (e.g. by deceptive email message)
into revealing confidential info (usually on a fake website looking like the organisation's)
which the scammer can use for identity theft or fraud etc.
Spoofing: faking an email header to look like it came from someone else. Often used in
phishing & spam to get people to trust the origin.
Pharming: a scamming practice in which malicious code is installed on a PC/server,
misdirecting users to fraudulent websites even if they type the correct URL.
Similar to Phishing but without a lure.
Click-jacking: a scam in which a disguised link (which cannot be seen or detected) is
inserted above a legitimate link. Users think they are clicking on a link/image but they
actually click on an invisible link above it which can contain a malicious program.
Good passwordsCapital and lowercase letters, numbers, symbols, no patterns (passphrase - longer
phrase is much safer - not with words from dictionary). Use a Password Manager.
Cri
min
al
PiracyUnauthorized duplication of copyrighted content that is then sold at substantially lower
prices in the 'grey' market
Hacker (white hat)Identify security gaps in an ICT system (also get ethical hackers - they get hired to test
security systems)
Cracker (black hat) Identify security gaps and use it for criminal purposes
Botnet
Many connected "bots" that include worms, trojans, spam, etc. Spread with other
people's infected computers (single: bot/zombie) over the Internet without them being
aware of their computers being used
Commonly used for a DDoS attack where masses of useless data or requests are sent to
a network or computer. This can reduce the speed drastically or crash the entire network.
Identity TheftThe illegal use of someone else's personal information (such as ID number) especially in
order to obtain money or credit
NETWORKS / INTERNET
23
Malw
are
(an
y m
alici
ou
s so
ftw
are
)
Spread through emails,
internet, flash discs,
pirated software etc.
Prevent through antivirus
software
Types
Adware: a software application where adverteising banners are
displayed while the program is running
Back door: a means of access to a computer system that bypasses
security mechanisms
Keylogger: a type of spyware that records a user's keystrokes
invisibly and sends it to the attacker
Ransomware: a type of malware designed to encrypt or block
access to your computer system and files until you pay a sum of
money (‘ransom’)
Rootkit: a collection of tools (programs) that enable
administrator-level access to a computer or computer network
Spyware: program in someone's computer to secretly gather
information about the user and send it to advertisers or others
Sniffer attack: small program that can read data packets over a
network
Trojan: a seemingly useful computer program that contains
hidden instructions which when activated by the user, perform a
malicious action (such as destroying data files)
Worm: a program that duplicates itself without the action of a
user and destroys data and files on a computer
NETWORKS / INTERNET
24
Gath
er
data
Research (published
information on internet &
books / newspapers,
interviews)
Evaluate reliability
Is the author / organisation reliable
Date of creation / update of
information (NB because it could
have changed in the meantime)
Does it match other sources?
Is this objective?
Good language / no spelling mistakes
Printed media e.g. books
Electronic sources eg. Internet
articles, e-encyclopedias
Already electronic / less typing time
More sources available
Easier to search content
More up to date
CopyrightA legal right / ownership of your own
intellectual material
Plagiarism
To present someone's work /
intellectual material as your own
(copy a source's information just like
that) without their
permission/acknowledging them
Opinion polls (to get people's
opinions)
E.g. Questionnaires, surveys,
interviews, votes
Closed questions: limited,
possible answers
Faster to complete
Less errors when data is being
captured
Easier to analyse / compare
informationOpen questions: unlimited
number of answers/opinions
Advantages of electronic /
online questionnaire (vs printed
questionnaire)
Online - Greater audience / more
variety of people
Distributed easier / easier to get back
Data validation can be done
Already electronic - No need to
retype
INFORMATION MANAGEMENT
Data refers to raw facts in
itself is not useful
Information is data that is
useful / processed
25
Rese
arc
h /
Data
pre
sen
tati
on
/ a
naly
sis
Spreadsheet
Large variety of graphs(note Access also has graphs)
Types: pie (to compare parts of a
whole), column (compare things
between different groups), line
(track changes over time)
Pivot Tables - to automatically
summarize data quickly
Made for / focuses on
calculations / functions /
numerical data
Database
Techniques like
Data validation (also in Excel) -
specify rules for data using criteria
Input masks - to enforce a pattern
e.g. number plate
Default values - where a common
value repeats often e.g. Gender,
Home Language
Primary key - unique field to identify
table records (compulsory and must
be unique)
Lookup wizard / dropdown list (also
in Excel) - to avoid mistakes & make
data input easier
Has objects like Queries, Forms
and Reports
Query - to extract specific
information
Report - to create neat reports with
grouping
Form - easy format for people to
enter data
Presentation of data better than
Excel: especially Report
Word processing
Styles - can then create an
automatic table of contents
Footnote1 - to give more
information about something
References:
Citations e.g. (Wikipedia, 2015) -
shortened version of source
Automatic bibliography - full list of
sources and all their information
Index - an alphabetical list of
words/conceptsand the pages on
which they appear (for ease of
reference)
Can work together on
documents with Track Changes
INFORMATION MANAGEMENT
Import refers to open a
file that is in a format
different from the format
the application creates on
its own.
Export refers to convert a
file into another format
than the one it is currently
in.