What is the difference between a flak gun and a flak cannon?

All cannons are guns, but not all guns are a cannon. A cannon is typically a large diameter firearm, NOT fired from the shoulder or hand, and fires in a direct fire mode (barrel angle less than 45...

A Machine gun can be hand held, and it functions by shooting rapid fire, while a cannon only shoots one large cannon and then you would need to re load it.

tank moves shoot machine guns and are more durable than cannons

Gordon brown

any firearm may be referred to as 'gun'. however, only semi-automatics are referred to as a pistol..........................