Torture is a process by which one exacts mental or physical cruelty upon another person for purposes of either interrogation or revenge for a past crime. Sometimes, a torturer commits acts out of sheer sadism. The process of torturing someone usually takes place over a prolonged period of time.
In most cases, the person being tortured is confined to a small space with restricted movement, allowing the torturer the ability to more efficiently torment them. In some circles, aggressive forms of interrogation conducted by military or law-enforcement agencies could be construed as acts of torture, and has given rise to controversy and scandal over the years.