A contract is a legally binding agreement that exists between two or more parties to do or not do something. An agreement starts from an offer and ends on consideration but a contract has to achieve another target i.e. enforceability.
The definition of a contract is given under section 2(h) of the Indian Contract Act, 1872, as follows:
“An agreement enforceable by law is a contract”.
Every promise and every set of promises, forming the consideration for each other, is an agreement”. After observing the definition of the agreement it is clear that a ‘promise’ is an agreement.
Thus, an ‘agreement’ is a bilateral transaction between two or more than two persons which involves proposal or offer by one and acceptance of such proposal by the other. In other words, it requires ‘plurality of persons’ because a single cannot enter into an agreement with himself.
As stated above, an agreement to become a contract must give rise to a legal obligation. If an agreement is not enforceable by law. It is not a contract.