Introduction to the Web

• What is the web?
  • The internet?
  • Email or IM?
• Why is the web (or what purpose does it serve)
  • To sell stuff?
  • To exchange information
  • A distributed documentation system.
• How is the web different from books?
  • World wide access
  • (semi) instant access
  • Hypertext
• What is Hypertext?
  • What is normal text?
  • How are web pages different?
  • A hyperlink - a link to text that does not immediately follow, or is not linear.
  • How do your read a novel vs how do you read a math book?
• HTML - the language of the web.
  • HyperText Markup Language
  • It consists of a series of tags, or commands, to mark formatting in the text.
    • For example, to make something bold
    • you use the tags <b> text in bold </b>
    • To make text in red
    • you use the tags <font color=red> text in red </font>
    • Note there is a tag to mark the beginning of the formatting instruction ( <b>)
    • and a tag to mark the end of the formatting instruction. ( </b>)
  • There are quite a few tags, but they all basically follow the same pattern
  • Here is a guide
  • You can view the html source code for a document by view->source
• The Hyperlink, or one special tag.
  • To add a link to another place in the document, you use a hyperlink
  • As we have seen in word, there are two pieces of information to do this
    • The words (text) we want to appear as the link
    • Where the text is that we are linking to (url)
  • Where the text goes is known as the Uniform Resource Locator
  • A hyperlink is constructed as follows:

    < a href="url"> text reference </a>

• The anatomy of the URL
  • Three parts
    • The protocol - the way we will retrieve the web page
    • The machine location - who has the web page
    • The file or program - which web page I want
  • http://users.edinboro.edu/dbennett/
    • Protocol: http - hypertext transfer protocol,
    • users.edinboro.edu - a machine in ross hall
    • dbennett/index.html - the welcome message
  • The location does not need to start with www.
    • http://douc54.cs.edinboro.edu/~bennett/poems/charge.txt
  • If no file is given, then index.html is assumed.
    • www.psc.edu
• For you
  • Later we will build our own web pages
  • The protocol will be http
  • The machine will be users.edinboro.edu
  • The file will be username/filename
  • We will create a number of files that we will post.