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.
Next: Operators Up: Scientific programming in C Previous: Variables. An expression represents a single data item--usually a number. The expression may consist of a single entity, such as a constant or variable, or it may consist of some combination of such entities, interconnected by one or more operators. Expressions can also represent logical conditions which are either true or false.