Torture is the practice or act of deliberately inflicting severe physical pain and possibly injury on a person, though psychological and animal torture also exist. Torture has been carried out or sanctioned by individuals, groups and states throughout history from ancient times to modern day, and forms of torture can vary greatly in duration from only a few minutes to several days or even longer. Reasons for torture can include punishment, revenge, political re-education, deterrence, interrogation or coercion of the victim or a third party, or simply the sadistic gratification of those carrying out or observing the torture. The torturer may or may not intend to kill or injure the victim, but sometimes torture is deliberately fatal and can accompany forms of murder or capital punishment. The aim may also be to inflict pain but without causing fatal injury, or sometimes any injury at all. In other cases, the torturer may be indifferent to the condition of the victim.
Although historically torture was sanctioned by some states, torture in the 21st century is prohibited under international law and the domestic laws of most countries. It is considered to be a violation of human rights, and is declared to be unacceptable by Article 5 of the United Nations Universal Declaration of Human Rights. Signatories of the Third Geneva Convention and Fourth Geneva Convention officially agree not to torture prisoners in armed conflicts. Torture is also prohibited by the United Nations Convention Against Torture, which has been ratified by 147 countries.