An operand is
|“||[a] data value or the symbolic representation of a data value in an expression. Operands may be numbers, character strings, functions, variables, parenthetical expressions in the body of a larger expression, and so on.||”|
"Symbolic representations of operands, such as variables and functions, are evaluated before they are operated upon by the operators in the expression. For example, in the expression "1 + 2", the operands are 1 and 2, and are operated upon by the + (plus) operator, which adds the operands together and returns the value 3."