Assume a function requires 20 lines of machine code and will be called 10 times in the main program. You can choose to implement it using a function definition or a macro definition. Compared with the function definition, macro definition will lead the compiler to generate, for the entire program,

"Macro Instruction"

Explanation:

A macro definition is a rule or pattern that specifies how a certain input sequence should be mapped to a replacement output sequence according to a defined procedure. The mapping process that instantiates a macro use into a specific sequence is known as macro expansion.

It is a series of commands and actions that can be stored and run whenever you need to perform the task. You can record or build a macro and then run it to automatically repeat that series of steps or actions.