Definition of dray. : a vehicle used to haul goods; especially : a strong cart or wagon without sides.
Expressions versus Equations. A difference between expressions and equations is what each represents. An expression shows a math relationship. One key to an expression is that there is no solution. An expression does not have an answer. An expression, however, can be evaluated. To evaluate an expression, substitute values for the variables.
expression. Is a constant, column, or function, and any combination of arithmetic, bitwise, and string operators. expression is an expression of the exact numeric or approximate numeric data type category, except for the bit data type.