I'm learning about vector projection. I understand how to perform it, but I still can't understand what it actually means and what it gives me.

Here is a common definition:

> 
> Vector projection of **a** onto **b**, gives the component
>  of **a** that is in the same direction of **b**.
> 
> 
> 

What does this mean?

Vectors are straight lines. **a** can't have a part of it in the direction of **b** and a part of it that isn't. A vector has one direction, it's a straight line.

I just can't understand this. I hope with some help here it'll finally click. Thanks