Definition of dray. : a vehicle used to haul goods; especially : a strong cart or wagon without sides.
The main difference between an equation and a function is the fact that an equation usually deals with a single input, whereas, a function can have numerous inputs. In mathematics, an equation is used to denote the equality between two expressions.
equation eÂ·quaÂ·tion (Ä­-kwÄ'zhÉn, -shÉn) n. A statement asserting the equality of two mathematical expressions, usually written as a linear array of symbols that are separated into left and right sides and are joined by an equal sign.