A person has possession of something if the person knows of its presence and has physical control of it, or has the power and intention to control it. [More than one person can be in possession of something if each knows of its presence and has the power and intention to control it.]
The law recognizes several kinds of possession. A person may have actual possession or constructive possession. A person may also have sole possession or joint possession.
A person who has direct physical control of something on or around his person is then in actual possession of it.
A person who is not in actual possession, but who has both the power and the intention to later take control over something either alone or together with someone else, is in constructive possession of it.
If one person alone has possession of something, possession is sole.
If two or more persons share possession, possession is joint.