Here's an example of a pseudo class (this link returns to the main page) .

This hyperlink has been rules for four different states. View the source to see the example.

1. a:link - the default setting as a hyperlink
2. a:visited - the setting after the hyperlink has been clicked
3. a:hover - this is the setting when the user has placed the cursor over the hyperlink
4. a:active - this is the setting when the user has pressed the hyperlink. Often this is not defined.

Keep in mind that these selectors must be defined in the order above to work properly.