North, south, east, and west

they are cardinal directions.

They are the four cardinal points. (cardinal directions)

The four cardinal directions are referred to as cardinal because they are the four main origin directions. if you look up the word cardinal in the dictionary one of the definitions is as follows...1. of prime importance; chief; principal: of cardinal significance.

Cardinal directions refer to the four cardinal points; north, west, south and east. On the contrary, ordinal directions are points that are located in between the cardinal points.