Confused about ViewportPointToRay

I have recently been researching rays and came across
ViewportPointToRay. All I know is that if you give it a x, y positions it will return a ray. Can somebody explain it in simpler terms than the dev hub thanks.

Basically casts a ray from the camera (where you’re looking) offset by the position provided. This returns a unit ray which is basically a ray that is 1 stud long (or you can say the magnitude of the ray is 1).