The term “debt” refers to a specific sum of money due by an agreement between the person who borrows that money (known as the “debtor”) and the person who lends that money (known as the “lender”).
“The action of debt lies where a party claims the recovery of a debt; that is, a liquidated or certain sum of money due him. The action is based upon contract, but the contract may be implied, either in fact or in law, as well as express; and it may be either a simple contract or a specialty. The most common instances of its use are for debts: (a) Upon unilateral contracts express or implied in fact. (b) Upon quasi-contractual obligations having the force and effect of simple contracts. (c) Upon bonds and covenants under seal. (d) Upon obligations imposed by statute.” Benjamin J. Shipman, Handbook of Common-Law Pleading § 52, 132 (Henry Winthrop Ballentine ed., 3d ed. 1923).