If your program needs to perform the same task many times, you can avoid having to type the same statements each time by writing a macro procedure. Macro procedures (commonly called macros) can be seen as text-processing mechanisms that automatically generate repeated text.
The term “macro procedure” rather than macro is used when necessary to distinguish between macro procedures and macro functions (a new feature of MASM 6.0 described in Section 9.6, “Returning Values with Macro Functions”).