A promise to do something between two parties or not must constitute a kind of mutual understanding in the pursuit of individual interests. Such an expression of the person`s will towards another is called a proposal. This expression of interest, with the intention of entering into an agreement that is valid and enforceable by law, is called an agreement. The whole operation leads to the entity called the contract. We can summarize these few lines as the whole process of forming the contract, but in the real picture, the process is quite complex and complicated. .