Cardinal directions are the basic directions we use to figure out where we are and where we need to go. They are North, South, East and West. Think of them like the four corners of your room - North is the corner opposite to the South corner, and East is the corner opposite to the West corner.
Have you ever seen a compass before? Well, a compass is a tool that helps us figure out which direction we are facing. If you hold a compass flat, it will show you where North, South, East and West are.
Why is it important to know these directions? Well, say you are lost in a big park - if you know which way is North, you can figure out which direction to walk to get to the exit. Or if you are trying to meet someone at a specific location, you can tell them to meet you on the East side of the building.
So, cardinal directions are just like the four corners of a room, and they help us figure out where we are and where we need to go.