We see a good looking guy, and think, "he's handsome".
Cute is personality and character. Anything but physical.
When a guy is shy, or funny, or dorky, or just.. being cute, we think "he's cute"
Well that is just my definition. But other times when we see an attractive guy, we say "he's cute", just because "handsome" is a stronger word, than "cute". And maybe the guy we're looking at isn't really THAT good looking.. so cute would be the safest way to describe him.
Handsome is mostly used when we see guys all dressed up, and formal. And smelling good :)
I guess what I'm trying to say is...
"Cute" guys could also be called "Handsome" at some occasions.
Cute guys are attractive but they have a lot more substance to them than just being attractive. They are generally also smart and funny and charming. The lines between cute and hot tend to be blurred though because if a girl likes a cute guy, he will become the sexiest thing around in her eyes and he will become hot to her because she likes him. And then girls tend to have different opinions on which guys are hot and which are cute. It varies from girl to girl.
Hot guys are generally so appealing that all we think about at first is doing physical things with them.
If a girl calls a guy handsome it could be because she doesn't want to give him a huge ego boost by calling him hot. Or it could be because a guy has pretty features that are very masculine.
Cute-usually accompanied by a good personality that makes them have a certain glow or appeal that makes you say aww! or just a sweet smile. There is something about cute guys that makes them seem more genuine and heartwarming which goes along with their good looks.
Hot- seriously you just want to jump their bones. more like a sexual attraction to their body/face/image.
Handsome- classically good-looking. can be hot but not usually in the cute category. more about the face and less about the body (but a good body does help). Everything is almost "fairy tale" good looking, as if he could be a model or you could picture him as prince charming.