Legal competence of parties to be held responsible for the terms of a contract or agreement. Underage or mentally incompetent people do not have legal capacity.
Legal competence to sign and be bound by a contract. One might lack capacity as a result of being a minor, being mentally challenged or not being of right mind. A contract signed by an incapable person is not binding.
The legal ability of people or organizations to enter into a valid contract. A person entering into a contract will have full, limited or no capacity to contract.