Title: Chapter 2 The Internet and World Wide Web
1Chapter 2The Internet and World Wide Web
2History of the Internet
p. 48
3The Internet
- How has the Internet grown?
p. 48
4Control of the Internet (W3C)
- World Wide Web Consortium (W3C)
- public, cooperative, and independent network
- set standards and guidelines
p. 49
5The Internet
- What are some services found on the Internet?
p. 48 Fig. 2-1
6Connecting to the Internet
- Dial-up accessmodem in your computer uses a
standard telephone line to connect to the
Internet
Digital subscriber line (DSL), cable telephone
Internet services (CATV), cable modem provide
connections using regular copper telephone lines
Connection is always onwhenever the computer
is running
Connection must be established each time you log
on. Slow but inexpensive
p. 49
7Accessing the Internet
- ISP, regional or national
- ATT, Earthlink
- OSP (AOL and MSN, for example)
- Provides expanded features like instant messaging
- Wireless Internet Service Provider (WISP)
- Verizon Wireless
p. 50
8Connecting to the Internet Backbone
Step 5. Regional ISP uses leased lines to send
data to a national ISP
Step 1. Request data from a server on Internet
Step 3. Data travels through telephone lines to a
local ISP
Step 4. Data passes through routers
Step 6. National ISP routes data across the
country
Step 2. Modem converts digital signals to analog
signals
Step 8. Server sends data back to you
Step 7. National ISP passes data to local ISP
p. 50 Fig. 2-2
9(No Transcript)
10How the Internet Works
- Internet addressingIP address
- Number that uniquely identifies each computer or
device connected to Internet
p. 51 Figs. 2-3 2-4
11The World Wide Web
What is the World Wide Web (WWW)?service of the
Internet
p. 52
12The World Wide Web
- Program that allows you to view Web pages
p. 52
13The World Wide Web
- Unique address for a Web page
- A web server delivers the Web page to your
computer
p. 54 Fig. 2-6
14The World Wide Web
- What is a hyperlink (link)?
- Built-in connection to another related Web page
location
- Item found elsewhere on same Web page
- Different Web page at same Web site
- Web page at a different Web site
p. 54
15The World Wide Web
- Program used to find Web sites and Web pages by
entering words or phrases called search text
p. 55 Fig. 2-8
16SearchingHow it works
- special software robots, called spiders build
lists of the words found on Web sites. - Web crawling
- starting points are lists of heavily used servers
and very popular pages. - indexing the words on its pages and following
every link found within the site. - spidering system quickly begins to travel,
spreading out across the most widely used
portions of the Web.
17Google
- began as an academic search engine.
- uses multiple spiders, usually three at one time.
Each spider could keep about 300 connections to
Web pages open at a time. At its peak
performance, using four spiders, their system
could crawl over 100 pages per second, generating
around 600 kilobytes of data each second. -
- When the Google spider looked at an HTML page, it
took note of two things - The words within the page
- Where the words were found
18The World Wide Web
- What are the basic types of Web sites?
p. 57 Fig. 2-10
19The World Wide Web
- Transfers data in a continuous and even flow
- Enables you to listen to the sound as it
downloads to your computer - Radio stations use streaming audio to broadcast
over the Web
p. 61
20The World Wide Web
- Consists of full-motion images with soundplayed
back at various speeds - MPEG (Moving Pictures Experts Group) is popular
video compressionstandard
p. 61
21The World Wide Web
- What is virtual reality (VR)?
- Use of computers to simulate real or imagined
environment - Appears as a three dimensional (3-D) space
- Used for games and many practical applications
p. 62
22The World Wide Web
- Programs that extend the capability of a
browser - You can download many plug-ins at nocost from
variousWeb sites
p. 62 Fig. 2-14
23The World Wide Web
- Short for electronic commerce
- Business transaction that occurs over the
Internet
Business to consumer (B2C)Sale of goods to
general public
Consumer to consumer (C2C)One consumer sells
directly to another
Business to business (B2B)Business providing
goods andservices to other businesses
p. 62 Fig. 2-15
24Other Internet Services
- File Transfer ProtocolInternet standard that
allows you to upload and download files with
other computers on the Internet
p. 66
25Other Internet Services
- What are newsgroups and message boards?
- Online area where users discuss a particular
subject
- Many Web sites use message boards because they
are easier to use
p. 67 Fig. 2-19
26Other Internet Services
- What is a mailing list (list serve)?
- Group of e-mail addresses given a single name
- When a message is sent to the mailing list,
everyone on the list receives the message - To add your name to a mailing list you must
subscribe to it to remove your name you must
unsubscribe
p. 67
27Other Internet Services
- Real-time typed conversation that takes place on
a computer
- Chat room is location on server that permits
users to discuss topics of interest
p. 68 Fig. 2-20
28Other Internet Services
- What is instant messaging (IM)?
- A real-time Internet communications service that
notifies you when one or more people are online
and allows you to exchange messages or files
p. 69 Fig. 2-21
29Internet 2
- developed by a consortium of universities and
technology companies in 1996 to provide vast
improvements in connection speeds. The goal of
the project has always been to stay three to four
years ahead of what is commercially available
through the public Internet. - Provides data at 10gbps (gigabits per second)
- More than 227 universities, libraries, public
schools and research institutions are connected
to Internet2. The network connects to more than
57 international high-capacity networks. - Peer-to-peer applications, high-definition
videoconferencing, remote manipulation of lab
equipment, and distributed computing are all
applications that are enabled by Internet2.
30Example of Internet 2 Use
- Internet2 nodes are connected to the Abilene
national backbone through regional fiber networks
with almost unlimited bandwidth capacity. -
- Musical Webcasts over the Internet can transfer
up to 250 megabytes of data per second over
Internet2. This is more than 4,000 times the rate
of a standard dial-up modem and more than 800
times that of a cable modem.