Habeas corpus is a legal procedure and writ that serves as a safeguard against unlawful detention or imprisonment. Its name comes from Latin, meaning "you have the body." The writ of habeas corpus is a court order requiring that a person held in custody be brought before a court to determine whether their detention is lawful. The custodian (such as a prison official) must justify the legal basis for holding the individual; if they cannot, the person must be released

. In practice, habeas corpus functions as a judicial inquiry into the legality of a person's confinement rather than a determination of guilt or innocence. It tests whether the authority detaining the person has lawful jurisdiction and authority to do so. The writ can be used by prisoners, detainees, or others acting on their behalf to challenge illegal imprisonment, including cases involving state or federal prisoners, immigration detention, military detentions, and extradition

. In the United States, habeas corpus is protected by the Constitution (Article I, Section 9, Clause 2), which prohibits suspension of the writ except in cases of rebellion or invasion when public safety requires it. Federal courts have the authority to grant habeas relief to prisoners held in violation of federal law, and the writ has evolved as a key mechanism for protecting individual liberty against arbitrary state action

. Overall, habeas corpus is a fundamental legal instrument designed to ensure that no person is held without lawful cause, providing a crucial check on executive and judicial detention powers

. Summary:

• Habeas corpus means "you have the body" in Latin.
• It is a court order to bring a detainee before the court to assess the legality of their detention.
• The custodian must justify the detention; failure to do so results in release.
• Used to challenge unlawful imprisonment, including criminal, immigration, and military detentions.
• Protected by the U.S. Constitution and serves as a vital safeguard of personal liberty