[osidak]

Please ignore the video above - that guy is just about clueless

he is comparing stranded vs solid core and that does not make a plenum cable. Plenum is basically a fire rating (how quick the jacket burns and also the fumes given off) - You want to use plenum anytime fumes can easily enter hvac distribution systems and also in case where a quick burning cable can help with the spread of a fire. This is dictated by your local fire codes

The extra "string" or fiber in a cable (in all but the cheapest cable) is there to aid in reducing stretch when pulling long runs. oh and ++++++ to running conduit to each room and while you are in there at least one draw string for future expansion.

CCA - copper clad aluminum - you do want to avoid this at all cost. Short runs are fine with this stuff but longer runs can get real funky. Not worth the small cost savings