HTML documents are defined by HTML elements.

HTML Element Syntax

An HTML element starts with a start tag / opening tag
An HTML element ends with an end tag / closing tag
The element content is everything between the start and the end tag
Some HTML elements have empty content
Empty elements are closed in the start tag
Most HTML elements can have attributes

Nested HTML Elements

Most HTML elements can be nested (can contain other HTML elements).

HTML documents consist of nested HTML elements.

HTML Document Eg:

Code:
<html>

<body>
<p>This is my first paragraph.</p>
</body>

</html>
HTML 3 Example Explained

The <p> element:

Code:
<p>This is my first paragraph.</p>
The <p> element defines a paragraph in the HTML document.
The element has a start tag <p> and an end tag </p>.
The element content is: This is my first paragraph.

The <body> element:

Code:
<body>
<p>This is my first paragraph.</p>
</body>
The <body> element defines the body of the HTML document.
The element has a start tag <body> and an end tag </body>.
The element content is another HTML element (a p element).

The <html> element:

Code:
<html>

<body>
<p>This is my first paragraph.</p>
</body>

</html>
The <html> element defines the whole HTML document.
The element has a start tag <html> and an end tag </html>.
The element content is another HTML element (the body element).