- 1. Chapter 10 Inside the Internetand the Web
- The Internet: A Network of Networks
- Internet Applications: Communication and Connection
- Inside the World Wide Web
Its a bit like climbing a mountain. You dont know how far youve come until you stop and look back. Vint Cerf 3.
- TheInternetis an interconnected network of thousands of networks linking academic, research, government, and commercial institutions.
The Internet:A Network of Networks 4.
- The Internet provides scientists, engineers, educators, students, business people, and others with a variety of services such as:
- Electronic mail(send/receive mail messages)
- Remote login (T elnet - access to other computers)
Internet Services 5. Internet Services
- Transferring files (FTP - accessing archives of data)
- Newsgroups (Usenet - on-line public discussions)
- World Wide Web (a collection of multimedia documents)
6. Counting Connections
- Today, the Internet connects computers to about every country in the world.However, the Internet is:
- growing too fast to measure its growth
- too decentralized to quantify
- a network with no hard boundaries
- The language at the heart of the Internet isTCP/IP
- Transmission Control Protocol/Internet Protocol
- Allows cross-network communication
Internet Protocols 8. Internet Protocols
- TCPbreaks messages into packets
- Each packet has all the information needed to travel from network to network
- Host systems calledRoutersdetermine how to route transmissions
9. Internet Protocols
- IPis the address for the packets
- Each Internet host computer has a uniqueIP Address
- Each address is comprised of four sets of numbers separated by periods, such as126.96.36.199
10. Internet Addresses
- The host is named using DNS (domain name system), which translates IP addresses into a string of names.
Each person on the Internet has a unique e-mail address created by having a squirrel run across a computer keyboard. Dave Barry 11. Internet Addresses
- Top level domains include:
- . edu - educational sites
- .net - network administration sites
- .org - nonprofit organizations
12. Internet Addresses
- An Internet address includes: email@example.com
- usernameis the persons mailbox
- hostnameis the name of the host computer and is followed by one or more domains separated by periods:
13. Internet Addresses
Examples: [email_address] UserPresidentwhose mail is stored on the hostwhitehousein thegovernmentdomain Userhazel_filbertat the server forLane County, Oregon, k-12school district 14.
- Direct (dedicated) Connection
Internet Access Options
- Computer has its own IP address andis attached to a LAN
- Files are stored on your computer
15. Internet Access Options
- limited connection using a modem
- Full access dial up uses SLIP or PPP via modem
- DSL service is newer, faster, and cheaper than ISDN
- Can share phone line with voice traffic
16. Internet Access Options
- allow Internet connections using shared TV cables
- Carry increased privacy and security risks
- provides connections using DirecTV satellite dishes
17. Internet Access Options
- Internet Service Providers (ISPs)
- local ISPs provide connections throughlocal telephone lines
- national ISPs offer connections on a nationwide scale
- The Internet use the client/server modelfor most Internet applications.
- In the client/server model a client program asks for information, and a server program fields the request and provides the requested information from databases and documents.
Internet Applications: Communication and Connection 19.
- Anemail serveracts like a local post office for a particular Internet hosta business, an organization, or an ISP.
- File servers are common within LANs, but theyre also used to share programs, media files, and other computer data across the Internet.
Internet Applications: Communication and Connection 20.
- File transfer protocol (FTP)allows users to download files from remote servers to their computers and to upload files.
- File compressionsaves storage space on disk and saves transmission time when files are transferred through networks.
Internet Applications: Communication and Connection 21.
- Anapplication serverstores applications- PC office applications, databases, or other applications - and makes them available to client programs that request them.
- An application server might be housed at anapplication service provider (ASP) -a company that manages and delivers application services on a contract basis.
- AWeb serverstores Web pages and sends pages to client Web browsers.
Internet Applications: Communication and Connection 22.
- WWWis a distributed browsing and searching system developed at CERN
- System was designed to give Internet documents unique addresses
- HTMLlanguage was created for encoding and displaying documents
- Browser software was built for viewing documents from remote locations
Inside the Web 23. Inside the Web
- Web pagesare made up of text and images
- AWeb siteis a collection of web pages
- AHome pageis the main entry to a Web site
- AWeb browserlike Netscape Communicator or Internet Explorer allows you to explore the Web by clicking links
Web site Jargon: 24. Inside the Web Hyperlinks (links) are words or pictures that act as buttons, allowing you to go to another Web page
- Links are typically underlined or displayed in a different color
25. Inside the Web
- Linksallow you to locate information without knowing its exact location (it may move from time to time)
- BackandForwardbuttons let you retrace your steps
- BookmarksandFavoritescan be set up to mark your favorite Web locations
26. Web Addresses PronouncedEarl like the name A typicalURLlooks like this: http://www.prenhall.com.beekman 27. Web Addresses
- Dissecting Web Page address:
Resource Page http:// www.vote-smart.org/ Path to the host help/database.html 28. Publishing on the Web
- AnHTMLdocument includes codes that determines the format, layout, and structure of a Web document
HTML (Hypertext Markup Language) HTML isnotWYSIWYG 29. Publishing on the Web
Appears like this on the screen
- Welcome to Computer Confluence Publishing on the Web
30. Publishing on the Web
- Programs that convert document format features into HTML codes
- Microsoft Word, FileMaker
31. From Hypertext to Multimedia
- Downloadableaudio and video
- Streaming audio and video
- Real-time liveaudio or video
Typical Web pages can contain: 32. From Hypertext to Multimedia
- Plug-Insare software extensions that add new features. Examples include