Further HTML information may be found in Appendix B.
HTML, or HypertextMarkupLanguage, is used by web programmers to describe the contents of a web page. It is not a programming language. You simply use HTML to indicate what a certain chunk of text is-such as a paragraph, a heading or specially formatted text. All HTML directives are specified using matched sets of angle brackets and are usually called tags. For example <B> means that the following text should be displayed in bold. To stop the bold text, use the </B> directive. Most HTML directives come in pairs and surround the affected text.
HTML documents need to have certain tags in order for them to be considered "correct". The <HEAD>..</HEAD> set of tags surround the header information for each document. Inside the header, you can specify a document title with the <TITLE>..</TITLE> tags.
Tip HTML tags are case-insensitive. For example, <TITLE> is the same as <title>. However, using all upper case letters in the HTML tags make HTML documents easier to understand because you can pick out the tags more readily.
After the document header, you need to have a set of <BODY>..</BODY> tags. Inside the document's body, you specify text headings by using a set of <H1>..</H1> tags. Changing the number after the H changes the heading level. For example, <H1> is the first level. <H2> is the second level, and so on.
You can use the <P> tag to indicate paragraph endings or use the <BR> to indicate a line break. The <B>..</B> and <I>..</I> tags are used to indicate bold and italic text.
The text and tags of the entire HTML document must be surrounded by a set of <HTML>..</HTML> tags. For example:
<HTML> <HEAD><TITLE>This is the Title</TITLE></HEAD> <BODY> <H1>This is a level one header</H1> This is the first paragraph. <P>This is the second paragraph and it has <I>italic</I> text. <H2>This is a level two header</H2> This is the third paragraph and it has <B>bold</B> text. </BODY> </HTML>
Most of the time, you will be inserting or modifying text inside the <BODY>..</BODY> tags.
That's enough about generic HTML. The next section discusses Server-Side Includes. Today, Server-Side Includes are replacing some basic CGI programs, so it is important to know about them.