pistol/handgun thing please help not a hunting question ok?

[Maddog]

Standard, Compact and Subcompact are the sizes of the handgun with subcompact being the smallest size and used a lot when a weapon needs to be concealed. A compensator is on the end of the barrel and can be used on pistols or rifles. It vents some of the muzzle blast through slots in the end of the barrel (usually upwards) to help prevent the barrel from coming up due to the reaction of the muzzle blast.

This is a very simplified answer and hope it helps. I'm not an expert but do shoot a lot. I am sure that a competition shooter or gun expert can give you a better answer.

[Scarface9]

What does Standard Compact Subcompact Competition and Compensator mean and stand for in handguns/pistols please help I do not know what they mean stand for and the difference in all of them please please help? (Not a Hunting question)