The Internet

A. Internet Basics

   1. Internet definition: a huge WAN, lots of computers interconnected
   2. History
      1969 - ARPAnet
      1970s - merged with UseNet
      1984 - 1000 hosts
      1986 - linked with NSFNet
      1995 - corporate, private sponsors provide bulk of backbone
      2000 - 50+ million users
   3. Internet Service Providers (ISPs)
      a. provide user services
   4. Internet Backbone
      a. Metropolitan Area Exchanges (MAEs)
      b. Network Access Points (NAPs)
   5. Internet Protocol (IP) Addresses
      a. four numbers (e.g., 198.112.168.223) indicating network/computer
      b. domain name replaces IP (e.g., www.scite.com), easier to remember
      c. domains
         i. older: com, edu, gov, mil, net, org 
         ii. newer: arts, firm, info, nom, rec, store, web
         iii. country: au, ax, ca, de, dk, fr, jp, nl, se, th, uk, us
      d. Domain Name Server (DNS)
         i. registers names
      e. Web addresses correspond to domain addresses but retrieved through
         special protocols (e.g., http - hypertext transfer protocol)
         i. Uniform Resource Locators (URLs)
      f. email addresses  USERNAME@DOMAINNAME
         a. email sent: SMTP (Simple Mail Transfer Protocol)
         b. email received and held: POP (Post Office Protocol)
   6. Data travels path
      - phone to local ISP
      - local ISP to Internet Backbone
      - backbone site to backbone site
      - backbone to remote ISP
      - remote ISP to remote server
   7. Cookies
      a. small files put on your computer when you connect to sites on web
      b. can be read when you access a site (gives a history of what you do)

B. Web Page Features

   1. Publishing
      a. HTML (Hypertext Markup Language), DHTML, XML
   2. Pictures
      a. JPEG (.jpg), GIF (.gif), PNG (.png)
   3. Animation/Video
      a. MPEG (.mpg) format
      b. Streaming video
   4. Audio
      a. WAV files
      b. MP3 files (and napster)
   5. Plug-ins (downloadable programs to extend browser's capabilities)
   6. Java applets (often with complex GUIs)
   7. Webcasting (information "pushed" out to users who express interest)

C. Internet/Web Services

   1. WWW
      a. Search engines (google, lycos, excite, infoseek, etc.)
      b. E-commerce
   2. email
   3. ftp (File Transfer Protocol)
   4. telnet
   5. newsgroups
   6. mailing lists
   7. chat rooms