Operand
In
mathematics, an
operand is one of the inputs (arguments) of an
operator. For instance, in
3 + 6 = 9
'+' is the operator and '3' and '6' are the operands.
The number of operands of an operator is called its
arity. Based on arity, operators are classified as
unary,
binary,
ternary etc.
In computer
programming languages, the definitions of
operator and
operand are almost the same as in mathematics.
Additionally, in
assembly language, an
operand is a value (an argument) on which the
instruction, named by
mnemonic, operates. The operand may be a
processor register, a
memory address, a literal constant, or a label. A simple example (in the
PC architecture) is
MOV DS, AX
where the value in register operand 'AX' is to be moved into register 'DS'. Depending on the
instruction, there may be zero, one, two, or more operands.
