Pseudo-classes
A CSS pseudo-class is a keyword added to the end of a selector, preceded by a colon (:), which is used to specify that you want to style the selected element but only when it is in a certain state. For example, you might want to style a link element only when it is being hovered over by the mouse pointer, or a checkbox when it is disabled or checked, or an element that is the first child of its parent in the DOM tree.
Pseudo-elements
Pseudo-elements are very much like pseudo-classes, but they have differences. They are keywords, this time preceded by two colons (::), that can be added to the end of selectors to select a certain part of an element.
- ::after
- ::before
- ::first-letter
- ::first-line
- ::selection
- ::backdrop