A prisoner is a person who is deprived of liberty against their will. This can be by confinement or captivity in a prison, or physical restraint. The term usually applies to one serving a sentence in prison.
Finnish serial killer Johan Adamsson, also known as "Kerpeikkari", in the 1849 lithography by Johan Knutson while he was imprisoned
To Visit the Imprisoned by Flemish artist Cornelis de Wael c. 1640
A scene in Newgate Prison, London
Physical restraint refers to means of purposely limiting or obstructing the freedom of a person's bodily movement.
Modern chain handcuffs made of hardened steel; Hiatt 2010
Iron wrist shackles with chains and padlock; Germany c. 17th century