communication, networks, the internet and the worldwide web
TRANSCRIPT
The Internet
What is a network? A collection of
computers and devices connected together via communications devices and media• Modems• Cables• Telephone lines• Satellites
message board
instant messaging
file transfer
Web
The Internet
What are some of the services found on the Internet?
chat
p. 2.3 Fig. 2-1
Next
Goal:
To function even if part of the network
were disabled or destroyed
Became functional
in September
1969
Goal:To allow scientists at different locations to
share information and work together
on military and scientific projects
History of the Internet
How did the Internet originate?
ARPANET
Networking project by Pentagon’s
Advanced Research Projects Agency
(ARPA)
Government
Cable companies
Satellite companies
Telephone companies
History of the Internet
Who provides the structure for the Internet today?
Networks from corporations, commercial
firms, and other companies
World Wide Web Consortium (W3C)
• Oversees research and sets standards and guidelines
Internet2 (I2)
• Internet-related research and development project
• Develops and tests advanced Internet technologies
History of the Internet
Who controls the Internet? The Internet is a public, cooperative, and
independent network No single entity controls or owns the Internet Several organizations advise and define
standards
High speed connection• Employees and students• Computers part of a local area network (LAN)• Connect to service provider through a high-speed connection
line leased from local telephone company
How the Internet Works
How can you connect to the Internet?
Dial-up access• Home or small business
• Computer, modem, regular telephone line
• Dial into an ISP or OSP
Newer high-speed technologies• Home and small business
• Digital subscriber line (DSL) – provides high-speed Internet connections over regular copper telephone line
• Cable modem- provides high-speed Internet connections through cable television network
How might data travel the Internet using a telephone line connection?
Step 1Step 1Step 2
Step 1Step 2
Step 3
Step 1Step 2
Step 3
Step 4
Regional ISP
Step 1Step 2
Step 3
Step 4
Step 5
Regional ISP
National ISP
Step 1Step 2
Step 3
Step 4
Step 5
Step 6
Regional ISP
National ISP
National ISP
Internet backbone
Step 1Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Regional ISP
Local ISP
National ISP
National ISP
Internet backbone
How the Internet Works
Step 1Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Step 8
Regional ISP
Local ISP
National ISP
National ISP
Internet backbone
1: You initiate an action to request data from the Internet.
2: A modem converts the digital signals from the computer into analog signals, which are understood by telephone lines.
3: Data (request) travels through telephone lines to a local ISP.
4: Data may pass through one or more routers before reaching its final destination.
5: The regional ISP uses lines, leased from a telephone company, to send data to a national ISP.
6: The national ISP routes data across the country to another national ISP.
7: Data moves from a national ISP to a local ISP and then to a destination server.
8: The server retrieves the requested data and sends it back through the Internet backbone to your computer.
How the Internet Works
What is an Internet protocol (IP) address? Number that uniquely identifies each computer or
device connected to the Internet Four groups of numbers, each separated by a period Number in each group is between 0 and 255
IP address 199.95.72.10
first part identifies network
last part identifies specific
computer
How the Internet Works
What is a domain name? Text version of an IP address Components are separated by periods Each domain name represents one or more IP
addresses
IP address 199.95.72.10
Domain name www.scsite.com
How the Internet Works
What is a top-level domain (TLD) abbreviation? Identifies the type of organization associated
with the domain Sometimes called dot com when TLD is com
Internet Corporation for Assigned Names and Numbers (ICANN)
Group that assigns and controls TLDs
How the Internet Works
What systems control domain names?
Domain name system (DNS)
System on the Internet that stores the domain names and their corresponding
IP addresses DNS server
Translates the domain name into its associated IP
address
The World Wide Web
What is the World Wide Web (WWW)? Also known as the Web A worldwide collection of electronic documents Each document on the Web is called a Web page Can contain text, graphics, sound, and video Can contain built-in connections to other documents A Web site is a collection of related Web pages
The World Wide Web
What is a Web browser? Also called a browser Software
program that allows you to access and view Web pages
Two popular browsers for personal computers• Netscape• Internet
Explorer
The activity of jumping from one Web page to another is surfing
The World Wide Web
What is surfing the Web? Links can point to an item on the same Web
page, a different Web page at the same Web site, or a separate Web page at a different Web site in another city or country
The World Wide Web
What are the parts of a URL?
protocol domain name path
http://www.nationalgeographic.com/travel/index.html
Web Publishing
Hardware
• Digital camera
• Scanner
• Sound card
• Microphone
• PC camera
What is needed for creating a Web page? Also called Web page authoring
Software to prepare HTML
• HTML (hypertext markup language)
• A set of special codes that format a file for use as a Web page
• Created with either:
• Word processing package
• Web page authoring software
Upload, or copy, the site to the
Web server
Locate a Web server to store your
site• Provided by many
ISPs and OSPs at no additional cost
• Provided by a Web hosting service for a monthly fee
Web Publishing
How do you deploy a Web site?
Apply to an official registrar
for a specific domain name
Register site with search engines
using a submission
service
• A Web-based business that helps register your site
Webmaster
Individual responsible for
maintaining a Web site and developing
Web pages
Web Publishing
What else might be needed to create a Web site?
Other Internet Services
What is e-mail? Electronic mail The transmission of messages and files via a
computer network Use an e-mail program to work with messages
create
receive
store print
sendforward
delete
Step 1Step 1
Step 2
Step 1
Step 2
Step 3
Step 1
Step 2
Step 3Step 4
How do you send an e-mail message?
Other Internet ServicesStep 1
Step 2
Step 3Step 4
Step 5
1 Start an e-mail program and point to the New Mail Message button
2 Click the New Mail Message button to display the Message window
3 Enter the recipient’s e-mail address, the subject, and the message in the Message window
4 Click the Insert File button to attach a JPG file containing a picture to the message. Locate the file on your hard disk and click its name. An icon for the file displays. Click the Send button to send the message.
5 When Sally receives the e-mail message, she opens the JPG file to view the picture.
Other Internet Services
What is an Internet e-mail address? A combination of a user name and a domain name
that identifies a user so he or she can receive Internet e-mail
user name or user-ID
A unique combination of characters that identifies you
at domain name
Identifies the mail server
mail server
The server that contains the mailboxes
Other Internet Services
How can you get e-mail? Most ISPs and OSPs provide an Internet e-mail
program and a mailbox on a mail server as a standard part of their Internet access services
Some Web sites provide e-mail services free of charge
address book
Allows you to store a list of names and e-mail addresses
mailbox
Storage location usually residing on the computer that connects you to the
Internet