A guarantee is a form of transaction in which one person, to obtain some trust, confidence or credit for another, engages to be answerable for them. It may also designate a treaty through which claims, rights or possessions are secured. It is to be differentiated from the colloquial "personal guarantee" in that a guarantee is a legal concept which produces an economic effect. A personal guarantee by contrast is often used to refer to a promise made by an individual which is supported by, or assured through, the word of the individual. In the same way, a guarantee produces a legal effect wherein one party affirms the promise of another by promising to themselves pay if default occurs.