What is the Internet

1
What is the Internet?

• The Internet, sometimes called simply
• "the Net,"
• is a worldwide system of computer networks
• a network of networks in which users at
• any one computer can, if they have
• permission, get information from any other
• computer.
• Email is the most widely used Net application.
• 1969

2
What is the World Wide Web?

• All the resources and users on the Internet that
  are using the Hypertext Transfer Protocol (HTTP).

3
The Web

• The WWW is no more (or less than) an enormous
  amount of information content connected by an
  enormous number of hypertext links.

4
The Backbone
5
Accessing the Internet/WWW

• Dialup- 56k Uses existing phone line. Slowest.
  - 25
• DSL - 1.5Mb Dedicated - Speed and access depend
  on physical distance from telco switch. 35-50
• Cable 1.5Mb and up Shared - 40
• ADSL 300-500k 3-4 miles
• IDSL 144k

6
How does it Work?

• Dialup using your existing (or secondary) phone
  line in your house. Speed is limited to about
  53kbs. Phone line is off-hook while online (no
  phone calls).
• DSL also uses existing phone line but modulates
  it to allow simultaneous phone usage. Also uses
  technology that allows higher speeds over those
  phone lines.
• Cable Makes use of unused bandwidth in your TV
  cable. Highest speeds for home users.

7
Internet Service Providers(ISP)

• Provide access to the Internet (gateway)
• Monthly fee
• Fee varies depending on access time and content
• Custom content

8
Fact or Myth?Hi-Speed Dialup Services

• How does HiSpeed dialup work?Data Compression
  and Image Optimization - Before the text and
  graphics that make up Web pages get sent to you
  over your phone line, dialup HiSpeed compresses
  them. Less data is sent .Memory Enhancement -
  Dialup HiSpeed uses caching technology to store
  elements of frequently visited Web sites so they
  load faster on future visits. Continuous
  Optimization - Dialup HiSpeed continuously
  optimizes the communication between your system's
  modem and the network while you are online. That
  means that is always working to shorten the
  amount of time it takes to connect you to the
  sites you visit.Pop-Up Blocking - Dialup
  HiSpeed may feature a pop-up blocker, which means
  that you wont have to wait for pop-up ads to
  load.
• This is an example of how some ISPs can claim to
  dramatically boost performance over standard
  telephone lines using a 56k modem.

9
AOL BroadbandJust the facts

• Actually, its AOL for Broadband.
• This is a Bring-your-own-access package
• You first must have a Cable or DSL account
  (Comcast or Verizon)
• You pay AOL extra to use the AOL services and
  software
• 15 comes with 5 hrs. dialup
• 25 comes w/ unlimited dialup

10
Search Engines

• Yahoo
• Google
• AltaVista
• AskJeeves
• Lycos
• WebCrawler
• Everybody and their brother