A written agreement is a legally binding document that outlines the terms and conditions of an arrangement between two or more parties. The three most common types of written agreements are PACT, CONTRACT, and COVENANT. A PACT is a formal agreement between two or more parties, usually in writing, to do or not do something. A CONTRACT is a legally binding agreement between two or more parties that creates an obligation to do or not do something. A COVENANT is a solemn promise made by one party to another, usually in writing, to do or not do something.