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.
Equations are commonly used in mathematics and chemistry. A mathematical equation is a statement that asserts that two different expressions are equal. The expressions are usually separated by an equals sign to show that one side balances the other.A chemical equation is a formula for showing a chemical reaction.