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
Here, a:visited, a:hover and a:active are called Pseudo-class selectors.
a:active must be specified after a:hover and a:hover must be specified after a:visited for the styles to take effect.