This is used to describe the size and quantity of conductors

in a cable. The first number specifies the gauge. The second

the number of current carrying conductors in the wire - but

remember there's usually an extra ground wire. "14-2" means

14 gauge, two insulated current carrying wires, plus bare ground.

-2 wire usually has a black, white and bare ground wire. Sometimes

the white is red instead for 220V circuits without neutral. In

the latter case, the sheath is usually red too.

-3 wire usually has a black, red, white and bare ground wire.

Usually carrying 220V with neutral.