Understanding HTML Elements: Structure and Composition of Web Pages

Learn the fundamental building blocks of HTML: HTML elements. This tutorial explains the structure of elements, the difference between start and end tags, empty elements, nested elements, and how they combine to create complex web page structures.

Understanding HTML Elements

What is an HTML Element?

An HTML element is the fundamental building block of an HTML page. It's defined by a start tag, some content (which can be text, other elements, or nothing at all), and an end tag. The start and end tags usually have the element's name enclosed in angle brackets (e.g.,  and  for a paragraph).

Example:

HTML

<p>This is a paragraph.</p>

In this example,  is the start tag, This is a paragraph. is the content, and  is the end tag.

Empty Elements

Some HTML elements don't have any content and are called empty elements. These elements don't require a closing tag. A common example is the line break element,  .

Nested Elements

HTML elements can be nested, meaning you can place elements inside other elements. This is how you build complex page structures. All HTML documents consist of nested elements.

Example:

HTML

<html>
<body>
  <h1>My Heading</h1>
  <p>My paragraph.</p>
</body>
</html>

    

Here, <body> is nested inside <html>, and <h1> and  are nested inside <body>.

Importance of End Tags

While some browsers might tolerate missing end tags for certain elements, it's crucial to always include them. Omitting end tags can lead to unexpected results and make your HTML invalid.

Case Sensitivity in HTML

HTML tags are not case-sensitive ( is the same as ), but the W3C (World Wide Web Consortium) recommends using lowercase for better readability and compatibility. W3Schools consistently uses lowercase tag names.

HTML Tag Reference

Tag	Description
`<html>`	Defines the root of the HTML document.
`<body>`	Defines the document's body.
`<h1>` to `<h6>`	Defines HTML headings.