What is Contract?
A contract is an agreement between two or more parties (people, groups) who promise to give and receive something from each other (in legal terms this is known as consideration).
All contracts are agreements; however, there are many agreements which are not contracts.
For example, if an acquaintance promised to pay for the petrol in return for a lift and later omitted to do so, you would not expect to take the matter to court. There was a certain agreement between you but there was no contract