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 definition. An expression of equality between two formulas in mathematics. The two formulas are written with an equal sign between them: 2 + 2 = 4 is an equation, as is E = mc2.