WHAT IS THE INTERNET

1
WHAT IS THE INTERNET?

• Mother of all networks
• Worldwide group of connected networks that allow
  public access to info. and services
  
• No single organization owns or controls

2
HISTORY OF THE INTERNET

• CA 1969 - network of 4 computers
• Advanced Research Projects Agency (ARPA) -
  ARPANET (DOD)
  
• sustain communications
• share research
• 82 million computers today

3
HOW THE INTERNET WORKS

• Internet Connections
• Dedicated lines thru school/work
• On-line information services
• Internet Service Providers (ISPs)
• Metropolitan area exchanges (MAEs) - computers
  that connect backbones
  
• Backbones - high-speed comm. Lines

4
HOW THE INTERNET WORKS

• Packet switching
• Divides data into packets - sends along best
  route - reassembles data
  
• TCP/IP (transmission control protocol/Internet
  protocol)
  
• IP - general communication rules
• TCP - handles details (duplicate/lost/out-of-order
  packets)

5
INTERNET ADDRESSES

• IP (Internet protocol) address (s)
• ex 198.105.232.4
• Geographic region Company/Org.
• Computer group Specific computer
• Domain name (text)
• ex thunder.temple.edu
• Domain name servers - find IP address

6
THE WORLD WIDE WEB (WWW)

• Started in 1991 in Switzerland
• Hyperlinks - links to other related documents
• Collection of hyperlinks known as the World Wide
  Web, WWW, W3, or the Web

7
THE WORLD WIDE WEB (WWW)

• How a Web page works - HTML tags
• HyperText Markup Language
• Uses tags and links to tell computer how to
  display pages
  
• within same document
• on same computer
• on different computer

8
THE WORLD WIDE WEB (WWW)

• Web browser software - displays pages
• Mosaic - 1993 1st graphical web browser - Marc
  Andreessen
  
• Netscape Navigator/Communicator
• Microsoft Internet Explorer
• Home Page - welcome page
• URL - Uniform Resource Locator
• http// - hypertext transfer protocol

9
THE WORLD WIDE WEB (WWW)

• Multimedia on the Web - Text
• Graphics
• Animation
• Audio
• Video
• Virtual Reality - artificial 3-D environment that
  you experience

10
THE WORLD WIDE WEB (WWW)

• Searching for info. on the Web
• Search engine - program that finds info. based on
  keyword(s) entered by user
  
• EX Yahoo!, Excite, Infoseek, Lycos, Altavista

11
INTRANETS AND FIREWALLS

• Intranets - internal networks
• Extranets - private networks including more than
  1 organization
  
• Firewalls - hardware/software used to restrict
  access to network data

12
OTHER INTERNET SERVICES

• E-mail
• FTP - File Transfer Protocol
• Gopher - find/retrieve text files
• Telnet - log onto a remote computer
• Usenet - newsgroups
• IRC - Internet Relay Chat

13
NETWORK COMPUTERS

• Designed to work while connected to a network
  (thin client, netPC)
  
• Less memory than PC
• Limited/no storage - storage provided by server
• Less expensive

14
COMPUTERS AT WORK

• Doing business on the WWW
• 24 hour access
• Global presence
• Lower marketing costs
• Easier update of info.
• Two-way communications
• Lower display/Storage costs
• Lower salesperson costs

15
IN THE FUTURE

• Internet and Web Future
• Business use of Web for electronic commerce will
  force expansion
  
• 100 -1,000 times faster within 10 yrs
• Browsers incorporated in software
• Integral part of education

16
IN THE FUTURE

• 80 of all computers connected by 2000
• Internet connections in everyday appliances
• More intelligent search capabilities
• Telephone, television, and radio merge into the
  Internet