From http://www.w3schools.com (Copyright Refsnes Data)

HTML tag

Example

A line break is marked up as follows:

This text contains a line break.

The tag inserts a single line break.

The tag is an empty tag which means that it has no end tag.

The tag is supported in all major browsers.

In HTML the tag has no end tag.

In XHTML the tag must be properly closed, like this: .

Note: Use the tag to insert line breaks, not to create paragraphs.

id, class, title, style

For a full description, go to Standard Attributes.