A legal document, usually in writing, giving details of a formal legally binding agreement, between two or more different people or groups. To be legally binding it must contain certain elements: it must contain an offer made by one party and accepted in its entirety by the other, it must include some form of consideration whether it be money, goods or services, and it must be properly signed by all parties to it, and dated.

Is the investigation of a business or person prior to signing a contract. A common example of due diligence in various industries is the process through which a potential buyer evaluates a target company or its assets for an acquisition.