Makefile actually is an old concept from UNIX development. Makefile is based upon compiling rules for a project and improve the project development efficiency. In a big project, there are many files in different folders. Of course you can write a DOS batch file to build whole project. But makefile can judge which steps should be done first, which steps can be ignored, and even more complicated goals. All of these are decided by the rules in makefile, instead of manually specified.