This appendix will introduce you to the most basic notions of writing Makefiles. For more information refer to [2].
To build a program you might need to perform multiple actions: launch compiler with the right flags, probably for each source file, and use linker. Sometimes you have to launch scripts written to generate source code files as well. At times the program consists of several parts written in different programming languages!
Moreover, if you changed only a part of the program, you might not want to rebuild everything but only those parts that depend on the source file changed. Huge programs ...