What is the Full Faith and Credit Clause?

Article IV, Section 1 of the US Constitution states, Full faith and credit shall be given in each state to the public Acts, Records, and judicial proceedings of every other state.

This is known as the Full Faith & Credit Clause.

What does the Full Faith and Credit Clause mean? 

Restated, Article IV requires that each state recognize the laws of every other state. The only exception to these rule concerns laws that violate the public policy of another state. In such a case, a state may refuse to recognize the legality of the foreign law or legal agreement.

• Example: State A issues a warrant for the arrest of Jane Smith. If the arrest warrant is transferred to State B for execution, State B may not intentionally fail to recognize the validity of the State As warrant.
• Example: State A grants marriage licenses and performs marriages for same-sex couples. State B must recognize these marriages as valid. State B may attempt to argue that recognizing the marriages violates public policy. This argument, however, has generally been rejected by the US Supreme Court.