In computing, a Macro is a shortcut to a task you do repeatedly. It is a single instruction that expands automatically into a set of instructions to perform a particular task.
Macro stands for "macroinstruction" - it is a programmable pattern which translates a certain sequence of input into a preset sequence of output. Macros can be used to make certain tasks less repetitive by representing a complicated sequence of keystrokes, mouse movements, commands, or other types of input.
In computer programming, macros are a tool which allow a developer to re-use code.