Horizontal Input

I was told that Input.GetAxis is more efficient than Input.GetKeyDown(KeyCode.W A S D).

as it can also be used on controllers

How do I detect which direction the horizontal axis is facing? Like is there a value of how “hard” it is moving in that direction? If so what is it called?

sorry for being stupid

I currently have
if (Input.GetAxis (“Horizontal”) > 0.1) {
GetComponent().velocity.x = (1);
if (Input.GetAxis (“Horizontal”) < -0.1) {
GetComponent().velocity.x = (-1);
but that sort of defeats the whole purpose of it as it is either moving left or right, nowhere in between.