Pseudo-class selectors are used to styling the state of an element during users' interaction. Pseudo elements style a particular part of an element. Pseudo-class selectors are preceded with a ':' (colon) while pseudo elements are preceded with '::' (double colon).
There are different types of CSS3 selectors that every aspiring web designer must know. These selectors include simple, attribute, pseudo-classes, pseudo-elements, combinators, and multiple