1: Valid contract 2: Void contract 3: Voidable contract 4: Illegal contract 5: Unenforceable contract
1: Valid contract has all essential elements and is enforceable
2: Void contract has no legal effect from beginning
3: Voidable contract can be cancelled by aggrieved party
4: Illegal contract is forbidden by law
5: Unenforceable contract cannot be enforced due to technical defects