what are the use of hover active and focus dynamic pseudo classes code example

Example 1: the syntax of pseudo-class in css

The syntax of pseudo-classes:

selector:pseudo-class {
  	property:value;
}

Example 2: What is a pseudo selector?

A pseudo-class is a selector that selects elements that are in a specific state, e.g. they are the first element of their type, or they are being hovered over by the mouse pointer