Hi,
Pseudo-classes are fictional element types that do not exist in HTML. In CSS1 there is only one element type which can be classed this way, namely the A element (anchor).
By creating three fictional types of the A element individual style can be attached to each class.
These 3 fictional element types are: A - unvisited link, A - active link, A - hover link and A -visited link.
Pseudo-classes are created by a colon followed by pseudo-class's name.
They can also be combined with normal classes, e.g.:
<a href=“#”....> Styling Pseudo-classes</a>
a:link {background: black; color: white}
a:visited {background: black; color: white}
a:hover{background: black; color: white}
a:active {background: black; color: red}