Web Design in a Nutshell, 3rd Edition

Elements

Elements are denoted in the text source by the insertion of special bracketed HTML tags. Most elements follow this syntax.

<element-name>content</element-name>

The element name appears in the start tag (also called the opening tag) and again in the end (or closing ) tag, preceded by a slash (/). The end tag works something like an “off” switch for the element. Nothing within the brackets is displayed by the browser or other user agent. It is important to note that the element includes both the content and its markup (the start and end tags ).

Tip

In XHTML, all element and attribute names must be lowercase. HTML is not case sensitive.

Consider this example of HTML markup that identifies the content at the beginning of this section as a second-level heading element and a paragraph element:

<h2>Elements</h2>
<p>Elements are denoted in the text source by the insertion of special bracketed HTML
tags. Most elements follow this syntax.</p>

Tip

In HTML 4.01 and earlier, the end tag for some elements is optional, and the browser determines when the tag ends by context. This practice is most common with the p (paragraph) element. Most browsers automatically end a paragraph when they encounter a new start tag. In XHTML, end tags are always required.

Some elements do not have content because they are used to provide a simple directive. These elements are said to be empty. The image element (img) is an example of such an element; it tells the browser to call a graphic file from an external location ...