It does both.
BZZZT wrong.
Check out the wording of the Bill Of Rights. People mistakenly think it enumerates rights. What it actually does is limit certain powers of government explicitly. E.g. "shall not be infringed."
It also limits those powers generally. Read the Xth amendment and then cite where else in the Constitution the federal government is permitted to stop me owning a bale of "dope," or, for that matter, a wagon load of it harvested with a combine, if I so desire?