A contract is an agreement binding on the parties. It creates a legal obligation on the parties to perform their obligation.
The law of contract bases itself on the common law. Case laws differ how a contract is formed and become legally binding on the parties.
An contract is enforceable against the party at fault or party in breach. Enforceability means that the innocent or injured party can sue the party at fault for legal remedies such as damages and specific performance.
There are 4 elements to contract formation. They are offer, acceptance, consideration and intention to create legal relation, capacity of the parties to contract and legality of the contract are also frequent concerns.
Only a very few types of contract regime writing e.g. sale of real properties, contracts can generally be made orally. However, whether writing is required or not, if there is a written contract, the parol evidence rule operates to exclude outside or extrinsic evidence.