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Discovering Computers 2010
Chapter 2The Internet and World Wide Web
The Internet
Also the Net Worldwide collection of networks Services on the Internet
Two of the Mostly widely used services– World Wide Web (WWW)– Email
Other services Chat rooms Instant Messaging VoIP (Voice over Internet Protocol)
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Evolution of the Internet
How did the Internet originate?
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Goal:To function if
part of network were disabled
Became functional
September 1969
ARPANET
Networking project by Pentagon’s Advanced
Research Projects Agency (ARPA)Goal:
To allow scientists at different
locations to share information
Evolution of the Internet
How has the Internet grown?
TodayMore than 550 million host nodes
1984More than 1,000 host nodes
1969Four host nodes (provide services and
connection to others on a network (UCLA, UCSB, Stanford, Utah)
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Evolution of the Internet
National Science Foundation (NSF) In 1986 connected its huge network of five
supercomputers (NSFnet) to ARPANET Became known as the Internet Until 1995, handle the bulk of the communication
activity In 1995, terminated its network on the Internet and
resumed its status as a research network
Evolution of the Internet
Who controls the Internet?
World Wide Web Consortium (W3C) Oversees research, sets standards and guidelines
Mission is to contribute to the growth of the Web
Nearly 400 organizations around the world are members of the W3C
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No onec—cit is a public, cooperative, andindependent network
Several organizations set standards
Internet 2
Not-for-Profit research and development project that connects universities and companies via a high –speed private network
Goals was to develop and test advanced network technologies that will benefit Internet users in the short-term future
Some projects that are now mainstream includes: Telemedicine and digital libraries
How the Internet Works
How can you connect to the Internet?
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High-speed connection
High-speed connection
Broadband Internet service
Cable, DSL,
fiber, radio signals,
and satellite
Broadband Internet service
Cable, DSL,
fiber, radio signals,
and satellite
Connection is always on—whenever the computer
is running
Connection is always on—whenever the computer
is running
Slow-speed technology
Slow-speed technology
Dial-up accessmodem in your computer uses a
standard telephone line to connect to the Internet
Dial-up accessmodem in your computer uses a
standard telephone line to connect to the Internet
Connection must be established each time you log on.
Connection must be established each time you log on.
Connecting to the Internet
DSL (digital subscriber line) – use the regular copper telephone lines
Fiber to the Premises(FTTP) – use fiber-optic cable Fixed wireless – use dish-shaped antenna on the
house or business Cellular radio network – use built-in compatible
technology or computers with wireless modems Wi-Fi (wireless fidelity) – uses radio signals Satellite Internet service – use satellite to satellite
dish
How the Internet Works
What are ways to access the Internet?
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An access provider is a business that provides individual and organization access to the Internet free or for a fee.
Three Categories:1. ISP, Regional or National (AT&T and EarthLink)2. OSP (AOL and MSN, two more popular)3. Wireless Internet Service Provider (ex. AT&T,
Boingo Wireless, Sprint Broadband Direct, T-Mobile, and Verizon Wireless)
How the Internet Works
What is a IP address?
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Internet protocol address Number that uniquely identifies each computer or device
connected to Internet Consists of four groups of numbers, each separated by a
period Number between 0 and 255 The first portion of each IP address identifies the network
and the last portion identifies the specific computer
How the Internet Works
What is a domain name?
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Text version of Internet protocol (IP) address The text in the domain name up to the
first period identifies the type of Internet server.
The last section contains the top-level domain (identifies the type of organization)
ICANN – assigns and controls top-level domains
The World Wide Web
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What is the World Wide Web (WWW)?
A worldwide collection of electronic documents
Each electronic document is called a Web page
Also called the Web
Can contain text, graphics, audio, video, and built-in connections
A Web site is a collection of related Web pages
Emerged in the early 1990s
The World Wide Web
What is a Web browser?
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Program that allows you to view Web pages The more widely used Web browsers for PC are:
InternetExplorer
GoogleChrome
Firefox
Opera Safari
The World Wide Web
What is a home page?
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The first page that a Web site displays Often provides links to other documents, Web pages or
Websites A link, short for hyperlink, is built-in connection to
another related Web page or part of a Web page
The World Wide Web
How do Internet-enabled mobile devices access the Web?
Use a microbrowser that displays Web pages that contain mostly text
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The World Wide Web
What is downloading?
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The process of a computer receiving information Depending upon connection speed, downloading can
take from a few seconds to several minutes
World Wide Web
What is a URL?
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Unique address for a Web page• Consist of a protocol, domain
name and sometimes the path to a specific Web page or location on a Web page.• Many web page addresses begin
with http:// (a set of rules that defines how pages transfer on the Internet• Not required
A web server delivers the Web page to your computer
The World Wide Web
How do you Navigate Web Pages?
Hypertext – refers to links in text-based documents
Hypermedia – combines text-based links with graphic, audio, and video links
Some people use the phrase, surfing the Web, to refer to the activity of using links to explore the Web.
Tabbed browsing – top of the browser displays a tab for each Web page you open.
The World Wide Web
How can you recognize links?
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A link can be text or an image
Pointer changes to a small handwhen you point toa link
Text links areusually underlinedand in a differentcolor
The World Wide Web
How do you Search the Web? Primary reason that people
use the Web is to search for specific information.
There are two types of search tools Search Engines Subject Directories
The World Wide Web
What is a search engine?
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Program used to find Web sites and Web pages by entering words or phrases called search text
Each word in the search text is known as a keyword.
Hits are the results of an search.
The World Wide Web
What is a subject directory?
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Search tool with organized set of categories and subcategories
Lets you find information by clicking links rather than entering keywords
Major disadvantage is that users have difficulty deciding which categories to choose.
The World Wide Web
What are the thirteen basic types of Web sites?
• Educational• Entertainment• Advocacy• Web Application• Content Aggregator• Personal
• Portal• News• Informational• Blog• Wiki• Online Social
Network
The World Wide Web
What is a portal?
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A Web site that offers a variety of services from one, convenient location, usually for free Searching, news, sports
and weather, Web publishing, reference tools, stock quotes, maps, shopping, e-mail, and online communities (Web sites that join people with similar interests)
The World Wide Web
What is a news Web site?
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Contains newsworthy material Stories and articles relating to current events, life,
money, sports, and the weather
The World Wide Web
What is an informational Web site?
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Contains factual information Created by organizations and government agencies
The World Wide Web
What is a business/marketing Web site?
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Contains content that promotes or sells products or services
Allows you to purchase products or services online
The World Wide Web
What is a blog?
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Short for Weblog An informal website
consisting of time-stamped articles or posts, in a diary or journal format
Uses a regularly updated journal format to reflect the interests, opinions, and personalities of the author and sometimes site visitors
Blogger – author of a blog
The World Wide Web
What is a wiki? Collaborative Web site that allows users to create, add
to, modify, or delete the Web site content via their Web browser
Are open to modification by the general public Difference between a wiki and blog is that users cannot
modify original posts made by the blogger. Popular wiki - Wikipedia
The World Wide Web
What is an online social network?
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Encourages members to share their interests, ideas, stories, photos, music, and videos
Popular social networking sites include Facebook and MySpace.
Media sharing Web site Share photos, music, and videos
The World Wide Web
What is an educational Web site?
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Learn how airplanesfly or how to cook ameal
Some colleges offer online classes and degrees
Offers avenues for formal and informal teachingand learning
The World Wide Web
What is an entertainment Web site?
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Offers an interactive and engaging environment featuring music, videos, sports, games, ongoing Web episodes, sweepstakes, chats, and more
The World Wide Web
What is an advocacy Web site?
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Contains content that describes a cause, opinion,or idea
The World Wide Web
What is an Web Application Web site?
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Allows users to access and interact with software through a Web browser on any computer or device that is connected the Internet
The World Wide Web
What is a content aggregator?
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Business that gathers and organizes Web content and then distributes, or feeds, the content to subscribers for free or a fee
The World Wide Web
What is a personal Web site?
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Web page maintained by private individual or family Reasons: sharing life experience with the world
or job hunting
