Search notes:
GNU Build System
aka GNU Autotools.
A developer might use the GNU Autotools to create a portable source code package that is later used by another user to compile an executable.
This other user (the source code compiler) should not be concerned about the autotools at all. Thus, he should not have to invoke autoconf etc.
The GNU Build System consists of
./configure
make
Misc
Eric S. Raymond
tweets that the reason why autotools were created are largely obviated by C99 and SuSv2 standardization.