Detention can be defined as holding a person lawfully against his will because of some crime the person committed or as a form of punishment. Detention can result in taking a person to a particular place (For Eg. Prison) or detaining him at private property or an unknown place.
During the detention, detainee can be interrogated for some information. The same term can be used for holding the property against the will of the owner due to same reasons.
Detainee is a term used for a person held in custody. During this period, a person loses his freedom of liberty. A person can be detained as a punishment, as a suspect or as a prisoner of war by armed forces. The term is more commonly associated with a situation when a person is held without any sort of warrant or charges against him. In other words, it can also be stated as withholding something that belongs to another individual. It can be property, personal belongings etc.