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Introduction to Computer Science The Internet and World Wide Web What is the Internet? The Internet is a large connection of networks. The Internet is not controlled by any agency. It contains a variety of services, one of which is the World Wide Web.

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introduction to computer science

Introduction toComputer Science

The Internet and World Wide Web

what is the internet
What is the Internet?
  • The Internet is a large connection of networks.
    • The Internet is not controlled by any agency.
    • It contains a variety of services, one of which is the World Wide Web.

When I took office, only high energy physicists had ever heard of what is called the World Wide Web…Now even my cat has its own page.

Bill Clinton, 1996

The Internet and World Wide Web

arpanet
ARPANET
  • The Internet started as ARPANET in 1969
    • US Dept. of Defense
    • Allow scientists to share information
    • Continue to function if parts were destroyed
    • Originally just four main computers housed in four different universities

The Internet and World Wide Web

nsfnet
NSFnet
  • National Science Foundation attached its network (NSFnet) to the ARPANET in 1986.
    • Became known as the Internet
  • In 1995, the NSF removed itself as the primary manager of the Internet.

The Internet and World Wide Web

the internet backbone
The Internet Backbone
  • The Internet backbone handles the bulk of Internet traffic.
    • The points of connection are National Access Points (NAPs), also called point of presence (POP).
    • An ISP/OSP that has a direct connection to a NAP is referred to as first-tier.

Read moreabout theInternetinfrastructure athttp://computer.howstuffworks.com/

The Internet and World Wide Web

connecting to the internet
Connecting to the Internet
  • "Dial" into an ISP or OSP using a phone modem, DSL, cable modem, etc.
    • ISPs and OSP have permanent connections to the Internet.
    • The ISP/OSP provides temporary access to the Internet through their connection
    • Once connected, you request web pages and other services, likee-mail and news groups.

The Internet and World Wide Web

america online
America Online
  • America Online is a very popular online service provider.
    • In addition to Internet access, AOL users get easy-to-use news and entertainment.
    • AOL provides a portal service to users, making access to different types of information easier.

The Internet and World Wide Web

broadband dsl and cable
Broadband: DSL and Cable
  • Broadband connections allow more data to travel between your computer and the Internet.
    • DSL and Cable are the two most common broadband choices for home users. Both cost approximately $40-$50 per month.
    • DSL (and ISDN) relies on the telephone cables managed by your local phone company.
    • Cable relies on the Coaxial cables managed by your television cable company.

“The number of broadband users in the US nearly tripled in the past two and a half years to more than 48 million subscribers, according to a report by the US Federal Communications Commission (FCC).”

http://www.computerweekly.com/

September 2004

The Internet and World Wide Web

dial up internet access
Dial-up Internet Access
  • “As prices dropped over the past year, broadband use at home has surpassed that of dial-up in the United States, reaching 53% of residential Web users in October, according to Nielsen/NetRatings. ”
  • http://yahoo.usatoday.com/
  • December 2004
  • Dial-up Internet access is still quite popular. Although it is a slower type of connection, it has some benefits:
    • Affordable
    • Uses standard phone lines
    • Adequate for most web surfing and e-mail

The Internet and World Wide Web

connection speed trends
Connection Speed Trends

The Internet and World Wide Web

bright idea
Bright Idea
  • Visit http://www.rr.com/rdrun/ and research cable internet access.
    • What type of internet access is the major competitor to cable?
  • Visit www.howstuffworks.com to find out how cable modems work.
    • What type of cable is used for cable internet?
    • Why do connections speeds vary with a cable modem?

The Internet and World Wide Web

world wide web
World Wide Web
  • The Web is a service on the Internet.
    • The Web is a collection of web documents on the Internet.
    • Each web document has an address, called a URL, or Uniform Resource Locator.
    • We use web browsers to display web pages, just as we use Word to display Word documents.

The Internet and World Wide Web

the w3c
The W3C
  • The World Wide Web Consortium
    • Non-profit organization based out of MIT (Mass. Institute of Technology)
    • W3C members include hundreds of software and hardware companies
    • Directed by Tim Berners-Lee, founder of the WWW
    • Sets standards for many areas of the Internet

The Internet and World Wide Web

web browsers
Web Browsers
  • Web browsers are applications that read web pages (HTML files).
    • Microsoft's Internet Explorer is the most common browser.
    • Others include Netscape Navigator, AOL, Opera, and Mozilla.
  • New browsers have better support for Web standards and greater security.
    • You should upgrade to a recent browser when possible.

The Internet and World Wide Web

microbrowsers
Microbrowsers
  • Handheld browsers have limited graphics capabilities
  • Some Web sites have alternate version sites for users with such devices
    • Obviously, web designers need to take into consideration the small screen size of handheld browsers when adding content and features to a site.

The Internet and World Wide Web

finding web pages
Finding Web Pages
  • Enter the domain name for a web site in the browser's address bar.
    • The browser finds the server and requests the default page (usually index.html).
    • home.html is another default.
    • The server honors the request and the browser downloads the web page from the server to your computer.
    • This whole process can take place in just a few seconds.

The Internet and World Wide Web

anatomy of a url
Anatomy of a URL

The Internet and World Wide Web

downloading
Downloading
  • When you view a Web page, you are viewing a copy of that page that has been downloaded to your computer.
    • You are not looking at the actual page on a Web server.
    • Pages that are large or contain a lot of graphics, download slower and will take longer to display.
      • Web designers need to find the balance between an attractive site and one that downloads quickly.

The Internet and World Wide Web

bright idea19
Bright Idea
  • Visit www.howstuffworks.com and research top-level domain names.
    • What was the intended purpose of .net and .com?
  • Visit www.google.com and do some research.
    • What is cybersquatting?
    • How much was spent for domain names like business.com and altavista.com?

The Internet and World Wide Web

web pages
Web Pages
  • Most Web pages are written in a language called HTML—Hypertext Markup Language.
    • Your web browser reads HTML and ‘translates’ it into a user-friendly web page with pictures and colored text.
    • HTML, it its basic form, controls the markup (look) of text.
      • Bold, italics, size, color, etc are all controlled by HTML
      • This word is <b>bold</b>, and this word is <i>italicized</i>.

The Internet and World Wide Web

html is plain text
HTML is Plain Text
  • HTML is a plain text language that can be written using any plain text editor.
    • Notepad is sufficient for writing even the most complex web pages.
  • Although programs like MS Word can save files as .html, this does not make them an ideal HTML editor.
    • There are hundreds of free and cheap HTML editors with various features available for download.
    • There are also popular programs such as FrontPage and Dreamweaver that create web pages.

The Internet and World Wide Web

basic web page
Basic Web Page

Marks the beginning of the HTML document

Marks the beginning of the body of the page. The part that people see in their browsers

Header information for the Web page. Used by search engines

Tells the browser which version of markup language is being used

The Internet and World Wide Web

cascading stylesheets
Cascading Stylesheets
  • Cascading Style Sheets control the formatting of HTML elements
  • HTML sets the structure of the document, while CSS gives the page color and other characteristics
    • One css file can be used to format thousands of web pages so that they all have a similar look.

The Internet and World Wide Web

uplodaing publishing
Uplodaing (Publishing)
  • After the page is made, upload the page to a Web server
  • Your ISP may provide server space for you
  • Your UCF fees include space on the UCF Web server
    • When you store a page/site on someone else's server, you have to follow their rules

The Internet and World Wide Web

file transfer protocol
File Transfer Protocol
  • FTP is the protocol used to upload and download files between a local computer and a server
  • You will use FTP to send your Web pages to the UCF server
    • You can FTP within the browser, or
    • You can download and install an independent FTP program. I use WS_FTP.

The Internet and World Wide Web

promoting your site
Promoting Your Site
  • Promoting your site will get more users there. This will increase traffic, and perhaps revenue
    • Give your URL to friends/family
    • Include your URL in your e-mail signature
    • Post your URL in discussion boards and newsgroups
    • Submit your URL to a search engine or web directory

The Internet and World Wide Web

search engines
Search Engines
  • Search Engines continually build a database of Web pages by collecting titles, descriptions, and page text.
    • They use programs called spiders or robots to search the Web and collect data.

The Internet and World Wide Web

a good search engine
A Good Search Engine
  • Two key factors make a search engine a good search engine.
    • The size of its database
      • The larger the database, the more likely your search results will contain the most recent information
    • The ranking of results based on searches
      • Relevant sites to the user’s search words must be located at the top of the listings. Otherwise, user’s will try a different search engine.

The Internet and World Wide Web

using search engines
Using Search Engines
  • Learn basic search techniques to improve search results
    • Use quotation marks for exact phrases.
    • Use + and – signs to include or exclude words.
    • Use “and” and “or” operators to widen or narrow the search.

The Internet and World Wide Web

web directories
Web Directories
  • Web directories are lists of web sites organized by topic.
    • A hierarchical structure is used to make finding sits for a particular topic easy.
    • Sites in web directories are added by people, so the site is really about the topic the user is interested in.
      • As the programming behind search engines improves, the emphasis on web directories declines.

The Internet and World Wide Web

portal sites
Portal Sites
  • Provide a variety of services and links on one page
    • Want you to make them your home page
      • The page that displays when you start your browser

The Internet and World Wide Web

web communities
Web Communities
  • Families of related (sometimes loosely) Web sites
    • WebReview provides articles and forums for web designers.
    • iVillage provides info on a wide range of topics geared towards women.
    • Yahoo Groups maintains web communities for all types of groups.

The Internet and World Wide Web

online communications
Online Communications
  • E-mail
    • The recipient's e-mail address is entered into the TO: field
    • The message is delivered to the appropriate mailbox and stored
    • The recipient logs into their mail server and uses Post Office Protocol (POP) to download the message to their local computer
  • Newsgroups
    • A newsgroup is a collection of threaded discussions about a particular topic
  • Chatting
    • Allows multiple users to communicate in real-time

The Internet and World Wide Web

netiquette
Netiquette
  • Netiquette is the code of acceptable behavior while on the Internet.
    • Keep messages brief
    • Use clear subjects
    • Don’t use all caps
    • Avoid sarcasm
    • Don’t write e-mails when upset
    • Include your name

The Internet and World Wide Web

multimedia
Multimedia
  • Combination of elements
    • text
    • graphics
    • sound
    • video
  • Multimedia can add richness to a Web site, but may greatly increase the download time.

The Internet and World Wide Web

web image formats
Web Image Formats

The Internet and World Wide Web

bright idea37
Bright Idea
  • Visit www.yahoo.com and research handheld devices for communication.
    • What is a blackberry?
    • What is wi-fi?
    • What is bluetooth?
  • Visit www.nokia.co to find out about mobile browsing.
    • What is the benefit of an xhtml browser?
    • Are choices extremely limited for xhtml-capable phones?

The Internet and World Wide Web

animated gif images
Animated GIF Images
  • An animated gif is a series of still GIF images shown in rapid succession to create an animation.
    • Movies are like this. A movie is a series of still photographs shown one-by-one so that we see movement.
  • Animated GIFs are fine for simple animations, but they can quickly become large (file size) and slow down the download process.
    • Flash animations can make cool animations with a relatively small file size.

The Internet and World Wide Web

thumbnail images
Thumbnail Images
  • Small versions of a large image
    • Very useful on the Web
    • Improves download time for the Web page
    • Let Web users know what the image is before they decide to wait for a possibly long download.

The Internet and World Wide Web

raster bitmap images
Raster (Bitmap) Images
  • Lite-Brite displayed images made up of individual pegs of color.
  • Bitmap images (raster graphics) work the same way.
    • However, a computer generated bitmap can produce millions of different colors and the points of light are very small.

The Internet and World Wide Web

creating bitmaps
Creating Bitmaps
  • We don’t use Lite-Brites, to make bitmap images, instead, we use computer hardware and software.
    • Adobe Photoshop
    • Jasc Paint Shop Pro
    • Microsoft Paint
    • Digital Cameras
    • Scanners

The Internet and World Wide Web

vector images
Vector Images
  • Like all vector images, the one above is made up of many polygon shapes. These shapes overlap each other in layers and together create the boat.
  • Vector graphics do not use a bit map structure. Instead, they use instructions that describe the size, shape, and color of the parts of the image.
    • This allows vector images to be resized quite easily without affecting quality and without affecting filesize.

The Internet and World Wide Web

audio on the web
Audio on the Web
  • Waveform is the digital reproduction of a natural sound.
    • Natural sounds are analog—they are varying strengths of a wave.
    • A digital sound uses sampling to produce a sound similar to the natural sound.

The Internet and World Wide Web

audio formats
Audio Formats
  • Popular formats include
    • WAV
    • MP3
    • WMA (Windows Media)
    • RM (Real Media)
  • Some formats can be played from the browser, others require a plug-in (supplemental application)

The Internet and World Wide Web

bright idea45
Bright Idea
  • Visit www.howstuffworks.com and research how mp3 files work.
    • How does the mp3 format make audio files smaller?
    • What is perceptual noise shaping?
  • Visit www.apple.com to research the AAC format.
    • What are some advantages of AAC over MP3?

The Internet and World Wide Web

common plug ins
Common Plug-ins
  • Plug-ins are often used when browsing the web. Some well know apps include
    • Acrobat Reader (Adobe)
    • Flash Player and Shockwave (Macromedia)
    • QuickTime (Apple)
    • Real Player (Real)
    • Windows Media Player (Microsoft)

The Internet and World Wide Web

streaming media
Streaming Media
  • Some audio and video can be played while it is downloading
    • Allows users to start enjoying the media without a long wait
    • Slow Internet connections can cause the media to stop playing intermittently while more of the file is downloaded

The Internet and World Wide Web

video on the web
Video on the Web
  • Video for the Web must be reduced in size and quality for fast downloads.
    • Most web video will have a grainy look and display in a small size.
  • Video can be embedded into a web page.
    • The user will need a player (plug-in) to watch the video.

The Internet and World Wide Web

e commerce
E-commerce
  • B2B (Business to Business) or B2G
    • The book publisher sells the text books to the UCF bookstore
  • B2C (Business to Consumer)
    • The UCF bookstore sells the books to students
  • C2C (Consumer to Consumer)
    • Students sell the books to other students

The Internet and World Wide Web

shopping carts
Shopping Carts
  • Technology that keeps track of a customers items prior to purchase.
    • Cookies are often used for this
  • Shopping carts allow us to shop around different parts of the online store before starting the check-out process.
    • Some online stores can even ‘remember’ what we put in our shopping carts the previous week or month.

The Internet and World Wide Web

online resources
Online Resources
  • http://www.google.com/help/basics.html
  • http://www.davesite.com/webstation/net-history.shtml
  • http://computer.howstuffworks.com/internet-infrastructure.htm
  • http://www.tucows.com/htmledit95_default.html
  • http://searchenginewatch.com/
  • http://www.albion.com/netiquette/corerules.html
  • http://userguide.website2go.com/p1161.html

The Internet and World Wide Web

the end
The End
  • Make sure you carefully read this chapter after going through this presentation on your own and in lecture.
    • Don’t feel like you have to read the whole chapter at once. Read five pages at a time, but do it.
    • Pay special attention to the terms in bold and italics. Can you define them without the book? Can you explain what they do and how they work?
  • Use the review material at the end of the chapter. This will help solidify what you’ve read and prepare you for the exams.

The Internet and World Wide Web