Originally Posted by
kdarejr
when I was younger what they call the bottom bracket was then the crank and crank arms ! how things change
No change. They are and always have been different pieces.
The "bottom bracket" (BB) is the thing that attaches the crank to the bike. It might or might not include an axle, but always includes bearings. (Nor does it include the frame cross tube - the "hanger tube".)
The "crank" is the axle and and arms assembly. One or both arms might not be detachable.