A contract is a mutual agreement between the parties, built on a relationship of trust in the performance of the obligations undertaken. A contract is a written agreement between two or more parties that entails mutual obligations and is enforceable.
That is, each agreement becomes binding (and only then is it called a contract) if the following conditions are met:
The existence of an offer to enter into a contract voluntarily;
explicit acceptance of the contract;
presence of mutual satisfaction (consideration).