Possession in a gun charge case is defined as it is in two ways. One is the actual possession of a gun. If someone is accused of having a gun on their person; they may have a gun in a holster on their hip, in their hand, or in their pocket. That is actual possession.
Constructive possession is another way that possession can be established regarding a gun. The government must prove that a person had the knowledge, the intent, and the power to exercise control over a firearm.