FNDE 103Information Technology

S.P. Samaranayaka Bsc(Hon’s),M.Sc(Computer Science)

IT-CenterUniversity of Peradeniya

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• What is computer• A computer is an electronic device that manipulates

information, or data according to set of instructions.• Set of instructions are called program.• That is computer has the ability to retrieve, process and

store data.

Computing

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Instructions

Storage

Physical components of computer such as the system unit(computer), mouse, keyboard, monitor etc…

Basically, hardware means what is tangible i.e., Somethingthat can be touched and felt.

Hardware

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• Collection of executable programs with proper documentation and configuration file

• That makes the computer work.

• Held secondary storages (HARD DISK, CD-ROM, DVD or FLOPPY DISK)

• Loaded (copied) into the RAM (RANDOM ACCESS MEMORY), as and when executing time.

• Intangible (cannot be touched and felt) as opposed to hardware.

Software

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• Working personnel, especially computer personnel, as distinct from the inanimate or abstract things they work with.

Live ware

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Central Processing Unit

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• The CPU is the brain inside the computer. • Main components of CPU

• Control Unit• Directs operation of the processor.• Controls communication and co-ordination between input/output

devices• Arithmetic Logic Unit

• Digital circuit that performs integer arithmetic and logical operations• Registers

• Small amount of memory associated with the CPU (registers)• uses to store data to be operated.

• It also access the main memory (RAM - Random Access Memory) within your computer.

• CPU and Main Memory are linked together by Buses.• Buses contains sets of parallel electrical conducting lines

Central Processing Unit

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• Primary storage• Directly accessible to the CPU

• Ex: RAM• Secondary storage

• Not directly accessible to the CPU• Ex: Hard disk

• Tertiary storage• Mount (plug) and unmount removable mass storage

• Ex: Pen Drive• Off-line storage

• Physically inserted into a system every time a users wants to access or edit data.

• Ex: Magnetic Tape

Hierarchy of storage

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• Collection of executable programs with proper documentation and configuration files

Software

Software

System Software Application Software

Packaged Software

Custom-Made Software

Utility Software

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• System Software• Controls the operations of a computer and the other types of

software that runs on the computer. • Ex: operating system, device drivers, programming languages, compilers,

assemblers ,translators and editors, and debuggers

• Application Software • Type of program that you use once the operating system has been

loaded. • Programs designed to perform specific tasks

Types of Software

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• Application software may be of two types.• Packaged Software(Generic)

• Programs prewritten by professional programmers that are typically offered for sale.

• Word-processing applications ,Spreadsheet applications ,Database applications ,Presentation applications

• Custom-Made Software• Programs written for a specific purpose and for a specific

organization• Banking system,Student Registration System

Application software

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• Utility software carries out all the day to day tasks in maintaining a computer system and its data files.• Ex: screensaver, virus checker, and system tools like disk

defragmenter.

• Certain utility programs are usually bundled along with the operating system.

Utility Software

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What is an operating System?

• Software program that enables the computer hardware to communicate and operate with other software.

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• It is loaded into the main memory when the computer is switched on.

HD

RAM

OS

LOAD OS TO RAM

Operating Systems….

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• The operating system does the followings on a computer:

• Manage computer resources such as memory,….• Controls a Computer’s Hardware• Runs a Computer’s Programs• Organizes Files

Operating Systems….

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• A part of the OS remains in the main memory until the computer is turned off.

RAMOS

Operating Systems….

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• User interfaces let user communicate with the computer.

• There are two types of them,• Command Line Interface (CLI)• Graphical User Interface (GUI)

Types of User Interfaces

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An Example of a CLI

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• Command Line Interface(CLI).• Users have to use keyboard commands to use the OS.• The user has to remember the commands.• At the beginning all the OS were running in CLI mode.• Even today some OSs give CLI as a part of their system tools. • Examples : MS DOS, Linux, UNIX, etc.

Operating System….

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An Example of a GUI

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• Graphical User Interface (GUI).• Contains graphics and icons and is commonly navigated by using a

computer mouse and can be used to invoke commands.• The GUI was first used on Apple Macintosh Computers• The GUI is very easy to learn and use i.e. user friendly.• Many of the modern operating systems come with GUIs

Example :Windows 3.1 , windows 95 , windows 98, windows ME , windows NT, Windows 2000, Windows XP(Home/Professional),Windows-8,windows-8.1,windows-10

Operating System….

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• Some operating systems support both GUI and CLI. Example : linux

Operating System….

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Hardware

OS

Applications

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Hardware

OS

Applications

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Layered Architecture

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Open source• Obtain with software source

code• User can get open software

for free of charge• Users can modify the

software• Users can install software

freely into any computer• No one is responsible to the

software

Proprietary Software• Purchased without software

source code• User must pay to get the

proprietary software • Users cannot modify the

software• Users must have a license

from vendor before install• Full support from vendor if

anything happened to the software

Open Source vs. Proprietary Software

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• Use of systems (especially computers and telecommunications) for storing, retrieving, and sending information.

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Information Technology

• A collaboration tool helps people to collaborate. • Purpose

• To support a group of two or more individuals to accomplish a common goal or objective.

• Collaboration tools can be • Non-technological nature

• such as paper, flipcharts, post-it notes• Software tools and applications

• such as collaborative software.

Collaborative tool

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• Communication• Email• Voicemail• Instant messaging (IM)• VoIP(Voice over IP) / video call

• Coordination• Online Calender

• Collaboration• Video conferencing• IM teleconferencing

Main types of Collaborative Tools

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• Email(Electronic mail )• Method of exchanging messages ("mail")

between people using electronic devices.• Use SMTP protocol

• Voicemail• Computer-based system that allows users

and subscribers to exchange personal voice messages

Communication

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• Instant messaging (IM)• Able to reach people within an organization in real-time

Communication

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• VoIP(Voice over IP) / video call• Group of technologies for the delivery of voice communications and

multimedia sessions over Internet

Communication

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• Activity of finding a suitable time for an event such as meeting, conference ..Etc.

• It is an important part of event planning • Carried out at its beginning stage.

• Online calendar best tool for event scheduling

Event scheduling

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• Comprises the technologies for the reception and transmission of audio-video signals by users at different locations

• For communication between people in real-time.

Video conferencing

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• Live exchange and mass articulation of information among several persons

• Machines remote from one another but linked by a telecommunications system.

IM teleconferencing

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• A seminar conducted over the internet.

webinar

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• Joint navigation through the world wide web by two or more people accessing the same web page at the same time

ex: share google document among multiple users

Co-browsing (collaborative browsing)

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• A diagram used to visually organize information.• A mind map is hierarchical and shows relationships among

pieces of the whole.

A mind map

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• Distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books.

• Ex: Google Drive

File Sharing

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• PowerPoint Online.• Google Slides.• Keynote.• LinkedIn SlideShare.• Zoho Show.• FlowVella.• LibreOffice Impress.

Online Presentation Software Tools

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Cloud Computing

• Using a network of remote servers hosted on the internet to store, manage, and process data.

• Rather than a local server or a personal computer.

• Use of hardware and software to deliver a service over a network (typically the Internet).

• Ex: Cloud Computing • Provider is google's gmail. • Gmail users can access files and applications hosted by google via

the internet from any device.

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Basic service model

• Infrastructure as a Service (IaaS)• Provides access to fundamental resources

such as physical machines, virtual machines, virtual storage, …

Ex - Customer Relationship Management, games, virtual desktop applications

• Platform as a Service (PaaS)• Provides the runtime environment for

applications, development & deployment tools, …

Ex - Database, web server, deployment tools

• Software as a Service (SaaS)• Allows to use software applications as a

service to end users. Ex - Virtual machines, servers, storage, networks

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Cloud computing architecture

• Components and subcomponents• Front end platform (fat client, thin client, mobile

device)• Back end platforms (servers, storage), • A cloud based delivery• A network (Internet, Intranet, Intercloud).

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Clouds Architecture

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Cloud Architecture

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Cloud Computing

Advantages• Cost Savings• Reliability• Manageability

• Flexibility for growth

• Efficient recovery• Access your data anywhere,

anytime.

Disadvantages• Security• Vendor Lock-In• Limited Control• Bandwidth issues.

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• A mobile app is a computer program designed to run on a mobile device such as a phone/tablet or watch.

Application of mobile devices

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Application of mobile devices to improve efficiency

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