Autoaim = Is like the autoaim that was included in retail for support of gamepads.
meaning : The player still needs to aim on his own just not that precise.
Aimbot = The cheater just needs to move around a little until his aim locks to closest person in view. (mostly on the head).
warning : No skill is required for this operation or what so ever.
Nope, it doesn't work this way.
What you described is very lame system that ruled the world in early '00s. Right now Aimbots that aren't made by idiots make aiming easier - eg. they move cursor to opponents just as the AutoAim does, it's: 1) automatically, 2) takes some time, it's not instant, 3) allows user to have some control over which opponents he aims at, and even which body parts he aims (he can move cursor, only it keeps going inside of opponent silhouette). In options you can set up aiming speed to avoid detection by automated scripts.
I know this sadly from the server owner side - it's nearly impossible to detect, and damn annoying if you try to organize some online tournaments.

Either way, my point is that:
there is no difference between SMART Aimbot and Autoaim.Agreed. "snap to" aimbots are obsolete.