Can anyone tell me the differences between "make clean" and "make clobber"? I searched but didn't find a useful answer.
Neither of these terms has a firmly established meaning. The Makefile author creates targets and gives them human-readable names; conventionally, clean means to remove things from a previous build, while clobber means to forcibly overwrite some previous results. The latter is less commonly seen or necessary.
In each case, for each Makefile, you should read any accompanying build documentation, or examine the Makefile and understand what it does, or, perhaps as a last resort, ask the author.