We can change the appearance of links not only like the normal elements, but also depending on some user actions. Like when the user takes their cursor over the link, or just when the user clicks the link or based on whether the link was previously visited or not. For this, we use the following link states:
a:visited - Applies if the link
was visited previously
a:hover - Applies when the user
takes the cursor over the link
a:active - Applies when the
link is just clicked
a:active are called Pseudo-class selectors.
a:active must be specified after
a:hover must be specified after
a:visited for the styles to take effect.