All right, we know how to set up a document, but all we've gotten so far has been dull, blank browser windows. Time to fix that.

You'll remember that I discussed the way tag-pairs are used to create containers in which content is held and certain rules applied to it; in short, the structural nature of HTML. We've already seen some of that in the way a Web document is split into two main sections: the document's header and body. In this chapter, we're going to get into some of the structures within the BODY.

Headings

The heading structures are most commonly used to set apart document or section titles. For example, the word "Headings" at the beginning of this section is a heading. So is this document's title (it's at the top of the page, in case you somehow missed it).

Remember that these heading structures go into the body of the document. The headings being discussed here have nothing to do with the HEAD structure from the previous chapter.

There are six levels of headings, from Heading 1 through Heading 6. Heading 1 (H1) is "most important" and Heading 6 (H6) is "least important." By default, browsers will display the six heading levels in the same font, with the point size decreasing as the importance of the heading decreases. Here are all six HTML pairs, in descending order of importance:

   <H1>Heading 1</H1>
   <H2>Heading 2</H2>
   <H3>Heading 3</H3>
   <H4>Heading 4</H4>
   <H5>Heading 5</H5>
   <H6>Heading 6</H6>

These six lines, when placed into an HTML document, will simply display the six levels of headings.

Since, as we have discussed, whitespace doesn't matter, you might think that the above block of HTML would just string the content into one line of text. However, because headings are meant for section titles and the like, they are defined as existing on a line by themselves. A heading always begins at the margin of a line and always forces a line break at the end of the heading. In other words, you cannot have two heading levels on the same line.

This also means that you cannot highlight text in the middle of a paragraph by marking it as a heading. If you try this, the paragraph will be split in two, with the heading text on its own line between the two pieces. (Later on, we'll talk about ways of highlighting text.)

If you have a browser which is set close to its default settings, you'll notice that the text for the last two headings gets pretty small. This leads to some page designers using H6 for the fine print at the bottom of pages. This is a mistake, not to mention an abuse of the heading structure. As you no doubt know, many browsers allow the user to set the size of each element, including the headings. If a user sets H6 to a size of 18 point, the fine print won't be so fine any more! Remember: you cannot guarantee that your document will appear to other people exactly as it does to you.

Paragraphs

As you might suspect, paragraphs are quite common in Web pages. They are one of the most basic structures in HTML. If you regard a document as a collection of structures and sub-structures, you may come up with something like:

The overall structure is a page. The page is composed of a number of sections, each of which is composed of one or more paragraphs. Each paragraph is composed of words, and each word of letters.

The beginning of a paragraph is marked by <P>, and the end by </P>. This tutorial is obviously filled with examples of this container.

Let's say you want to create a paragraph. You start to wonder, "What happens if I hit return at the end of every line in the paragraph? Should I make the paragraph just one long continuous line? What if I accidentally put too many spaces between words?"

At this point, you should once again be saying to yourself: whitespace doesn't matter. You could put each word on its own line, and the paragraph would look completely normal. In fact, no matter how much whitespace you put between words, whether returns or spacebar hits, the words will be separated by one space in a Web browser.

Got all that? If you're not sure you completely understand, go through the section again -- or better still, try it on your own.

Line Break

So what if you want to end a line after a certain word, but don't want to start a new paragraph? Well, what you need is a line break, which is invoked by using the <BR> tag. This forces a line break wherever you place it in the content (that is, whatever is after the <BR> tag will start from the left margin of the next line on the screen.)

And no, there is no </BR> tag. The line break tag is -- that's right! -- an empty tag. And when you think about it, this makes sense. The concept of a line break beginning and ending doesn't really work, since a line break is a one-shot occurrence.

Blockquote

Blockquotes are handy for those long pieces of text which are quoted material and therefore need to be set apart and indented. That is exactly what blockquote does. For example:

This section of text is surrounded by the blockquote tags. A blockquote can exist inside of a paragraph, and always lives on its own line (which is to say, there is an implied line break before and after the blockquote, just as with headings or paragraphs themselves).

   <blockquote> ...text... </blockquote>

Lists

There are three main types of lists. I've included the heading here because lists are basic text structures -- they just need a lot more explanation. That's what you'll find in the next section.