Computers, The Internet& The Web

Jacie YangTexas State University

Computers

Computers

• Hardware– Motherboard– Graphic Card– CPU (Central Processing Unit)– RAM (Random Access Memory)– Hard drive– CD/DVD drive

• Operating Systems• Software

Operating Systems• Windows (PC)– Windows XP– Windows Vista– Windows 7

• Mac OS– Classic Mac OS– Mac OS X

• Linux

• OS Market Share

Display

• Pixel– Smallest addressable screen element– Also a unit for image dimensions

• Screen display– Lower than 1024x768– 1024x768– Higher than 1024x768– Screen display market share

Files

• File size– 1 bit= 0 or 1– 1 byte= 8 bits– 1KB= 1024 bytes (1024=210)– 1MB= 1024MB– 1GB= 1024MB– 1TB= 1024GB

• So, do you need a 32G iPhone or a 64G iPhone?

Internet=Web?

The Internet

Defining the Internet

• The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide (Wikipedia).

• An electronic communications network that connects computer networks and organizational computer facilities around the world (Merriam-Webster).

History of the Internet

• History of the Internet• In the 1960s (the Cold War)• US government created Defense of Advanced

Research Projects Agency (DARPA)• US Military was concerned about survivability

of their centralized communication networks• First two nodes of the ARPANET– UCLA, School of Engineering & Applied Science– SRI International in Menlo Park CA

What Can You Do on the Internet?

• E-Mail (electronic mail)• Instant Message (AOL, MSN Messenger, etc)• BBS (Bulletin Board System) • VOIP (Voice-over Internet Protocol)• WebCam• File sharing (FTP)• Media Streaming (webcasts, podcasting)• The Web

The Web

Defining the Web

• The Web: World Wide Web, or WWW.• A system of interlinked hypertext documents

accessed via the Internet (Wikipedia).• A part of the Internet accessed through a

graphical user interface and containing documents often connected by hyperlinks —called also Web (Merriam-Webster).

• The Web can only be accessed through Web browsers!

History of the Web

• 1989-1990• Tim Berners-Lee• Built “Hypertext project”

called WorldWideWeb.• Creator of HTML

(Hypertext Markup Language).

Mosaic: First Web Browser

• 1992-1993• Made the Web

popular and accessible to the public.

• Later become Netscape (1994).

Web Browsers

• Internet Explorer (Microsoft, 1995)• Opera (Opera Software,1996)• Firefox (Mozilla Corporation, 2004)• Safari (Apple, 2005)• Chrome (Google, 2008)

• Timeline of Web Browsers• Browsers Market Share

Web Browsers 2010/5/16

How does the Web work?

• URL: Uniform Resource Locator– i.e. http://www.txstate.edu

• http:// – Hypertext Transfer Protocol

• www – World Wide Web

• How does the Web work?• WWW in Plain English

Multimedia on the Web

• Text• Images• Audio• Video

• Let’s take a look at those elements on the Web.

Images on the Web

• JPG/JPEG (Joint Photographic Experts Group)– Supports true color– Is usually the file format of digital cameras

• GIF (Graphic Interchange Format)– 256 colors– Good for graphics with limited colors

• PNG (Portable Network Graphics)– Best when you have combination of photos and

text

Audio and Video on the Web

• Popular audio formats:– MP3, ACC, WMA

• Popular video formats:– AIFF, WAV, MOV (QuickTime), MP4, RM

• Supports both audio and video:– ogg

Search Engines

Defining Search Engines

• A web search engine is designed to search for information on the World Wide Web (Wikipedia).

• Computer software used to search data (as text or a database) for specified information; also : a site on the World Wide Web that uses such software to locate key words in other sites (Merriam-Webster).

How Do Search Engines Work?

• How Search Engines Work• Web Search Strategies

Popular Search Engines

• Search Engines– Google– Bing– Yahoo– Ask.com

• Meta-search engines– Ixquick– Clusty