It doesn't unless you write your Makefile to use them. In the Makefile you are looking at, it probably includes rules.mk or make.mk with include directives in the Makefile:
Code:
include rules.mk
include make.mk
Or there might be some Makefile-generating script somewhere that uses those. But in general, all make needs to run is Makefile, nothing more, unless your Makefile is referencing other files like rules.mk, or blahblah.mk, or okeedokee.txt, or whatever.
IIRC, traditionally, when people set up Makefiles and used files named rules.mk and make.mk, they put all the platform-independent stuff in make.mk, and all the platform-specific stuff in rules.mk. And then their Makefiles just included those, and each Makefile contained the things specific to each thing that was being built (like source filenames and such).
