LBSC 690: Week 2 HTML, The Internet

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LBSC 690 Week 2HTML, The Internet

• Jen Golbeck
• College of Information Studies
• University of Maryland

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A Short History of the Internet

• 1969 Origins in government research
• Advanced Research Projects Agency (ARPAnet)
• 1983 Design adopted by other agencies
• Expansion from educational institutions to
  corporations
• 1991 World Wide Web added point-and-click
  capabilities

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The Internet

• Global collection of public networks
• Private networks are often called intranets
• Each organization maintains its own network
• Use of shared protocols
• TCP/IP (Transmission Control Protocol/Internet
  Protocol) basis for communication
• DNS (Domain Name Service) basis for naming hosts
• HTTP (HyperText Transfer Protocol) World Wide Web

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Packet Routing (TCP/IP)
128.0.1.5
63.6.9.12
4.8.15.2
52.55.64.2
18.1.1.4
192.28.2.5
(Much simplified) Routing table for 4.8.15.2
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Addresses and Domain Names

• Every computer has an IP address
• E.g. 128.135.20.100
• Hard to remember, and hard wired
• Domain names are short cuts to IP addresses
• umd.edu, facebook.com, etc

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Domain Name Service (DNS)

• Domain names improve usability
• Easier to remember than numeric IP addresses
• DNS coverts between names and numbers
• Written like a postal address specific-to-general
  
• Each name server knows one level of names
• Top level name server knows .edu, .com, .mil,
• .edu name server knows umd, umbc, stanford,
• .umd.edu name server knows wam, glue, ttclass,
• .wam.umd.edu name server knows rac1, rac2,

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Domain Names

• Unsponsored
• .biz .com .edu .gov .info .int .mil .name
  .net .org
• Sponsored
• .aero .asia .cat .coop .jobs .mobi .museum
  .pro .tel .travel
• Infrastructure .arpa .root
• Proposed
• .berlin .bzh .cym .gal .geo .kid .kids
  .lat .mail .nyc .post .sco .web .xxx
• Deleted/retired .nato
• Reserved
• .example .invalid .localhost .test

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If you want one

• You need a web host
• Company to host your web pages
• Alternatively, you can do it yourself, but it
  requires a lot of infrastructure (and
  permissions) you dont have
• Cost ranges from 5/month (e.g.
  http//tinyurl.com/dw6qd ) and up depending on
  services
• You register for a domain name and point it to
  the host
• Cost is about 35/year (less if you buy for
  multiple years)

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The Web

• Not the same thing as the Internet
• Internet is the network of computers that sends
  information around (email, web pages, chat,
  skype, file transfers, etc)
• The web is a layer on top of the internet that
  sends files in a certain way (using HTTP)
• 1991 - now

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Foundations of the Web

• TCP/IP
• DNS
• HTTP

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Standards

• No one owns the web or the internet
• Platform and software independent - it should
  work the same everywhere
• W3C - World Wide Web Consortium
• A group of people (universities, businesses,
  governments, etc) who decide by committee what
  the web will be and how it changes
• Some people modify standards
• BAD!
• E.g. a web page that only works in Internet
  Explorer

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Why Code HTML by Hand?

• The only way to learn is by doing
• WSIWYG editors
• Often generate unreadable code
• Ties you down to that particular editor
• Cannot help you connect to backend databases
• Hand coding HTML allows you to have finer-grained
  control
• HTML is merely demonstrative of other important
  concepts
• Structured documents
• Metadata

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Todays Tutorial

• Your first HTML page
• Uploading your page to the Web server via FTP

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Hello World HTML
lthtmlgt ltheadgt lttitlegtHello World!lt/titlegt lt/headgt
ltbodygt ltpgtHello world! This is my first
webpage!lt/pgt lt/bodygt lt/htmlgt
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Uploading Your Page

• Connect to wam.umd.edu
• Change directory to /pub/USERID
• Upload files

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Tips

• Edit files on your own machine, upload when
  youre happy
• Save early, save often, just save!
• Reload browser