What is the difference between acne and pimples?

I think that the difference between acne and pimples is this.

Acne can sometimes be all over your face and clumped together as well as pimples but pimples are more likely to be spread out and would usually be more likely to fall on top on your forehead. I also think that acne is more likely to be all over you face although many people say that they are the same because pimples are one form of acne. Well, if this is true then there is very little difference between the two.