Bx cable is known as armored cable. Wires are covered by aluminum or steel flexible sheath that is somewhat resistant to damage.
Single strands of conductor wire are pulled through conduit that is the safest method for wiring for durability purposes.
These different types of wiring carry electrical current from the panel to the device being fed. Wiring is sized according to the load demand required. Check the rated required load requirements marked on each device to determine the needed size wire to carry the needed load.
