A more thorough explanation:

An invalid contract is a type of contract that is not legally enforceable. A contract is an agreement between two or more parties that creates obligations that are enforceable or recognizable by law. It can be in writing or verbal.

For example, if a person signs a contract to sell a car, but the car has already been sold to someone else, the contract is invalid. The contract cannot be enforced because the seller did not have the right to sell the car.

Another example of an invalid contract is when one party is forced or coerced into signing the contract. For instance, if a person is threatened with physical harm if they do not sign a contract, the contract is invalid because it was not entered into voluntarily.

Invalid contracts can also occur when the terms of the contract are illegal or against public policy. For example, a contract to sell illegal drugs is an invalid contract because it is against the law.

In conclusion, an invalid contract is a contract that is not legally enforceable due to various reasons such as fraud, duress, illegality, or lack of capacity. It is important to ensure that a contract is valid before entering into it to avoid any legal issues in the future.