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.
An expression is a group of mathematical symbols representing a number or quantity. Expressions never have equality or inequality signs like =, >, <, â  ,â¥ ,â¤. An identity is an equation that is always true, no matter what values are chosen.