Yes. 4.0 is perfect, but rare that someone would get all A's over a number of years.. If you have a 3.5 GPA or so it is considered a very good GPA as grades are averaged. For example, if I got 3 A's and 2 B's, I would have an average of 4+4+4+3+3= 18/5 = 3.6 GPA
I completely agree with ibmistersmile. The only thing I'll add is, different schools sometimes weight grades differently, so check out your school's policy first to see your exact grade... but all A- is not a 4.0 <3
In my school, an A was an A. It counted for the same amount ultimately. Some schools however rate their grade a little differently. There were neighboring schools nearby that offered a lot of college prep courses that would allow you to potentially get an A+. I know students who had a 4.0, but they weren't the valedictorian because someone had a 4.1 or even higher. I think it's strange to be able to get higher than a 4.0, but that is probably just because my school didn't offer it. Check with your school to see what their scale is.