Yay on the shorts. Shorts that stop at the knee or below are the only shorts I will ever wear, so I am a fan of those.
Katie, it has to do with the length. Unless you climb or know about climbing, they are going to be called capris because they stop somewhere in the middle of the calf. I mean, you can call them capris, clam diggers, pedal pushers, or high waters, because they are all the same thing - pants that stop below the knee and above the ankle. (High waters would be the longest version.)