You’ll notice on the previous page’s example that the style of the link reacted when you moused-over it. This provides a visual idicator to a visitor that the link is still active, should they look for it again after it was visited (set to gray out in the :visited state).

Many pseudo-classes react to events like these, which we generally refer to as states.

The most common pseudo-class states:

:hover (event is triggered when mouse hovers over)
:active (event is triggered while element is selected)

CSS

selector:hover {}
selector:active {}

/* The word selector in the above is replaced with
the normal CSS selectors used to identify elements. */
p:hover {
  color: green;
}

NOTE: Any pseudo-class that relies upon mouse information (such as the ones below) will not translate to mobile devices.

“When would I use states?”

“Quite often!” Many elements can utilize hover states, although it is most commonly used with links.

Buttons are built with states. Active states make a button feel more real by slightly changing the color when the user presses it. But this can be used for any pressed effect.

If the example below, the button utitlizes :hover to change the appearance of the text, and :active to give the experience of a button press.