• Macro is a series of instructions that the programmer can call from anywhere in the program. It's primarily used for modular programming. As a result, using a macro, the same set of instructions can be used several times as needed.
• During compilation, the macro's identifier is substituted by the actual declared instructions, therefore there is no calling and returning. A macro definition is a set of instructions that can be used to facilitate modular programming. A procedure is a collection of instructions that can be invoked repeatedly to execute a specified task.
• It is used for tiny groups of instructions, usually less than ten.

Read More: Explain the various types of registers?