My rear tail lights seem to be out.  I thought that the tail lights
share the same bulb as the brake lights?   Here is my following
situation:

Working:
*Both rear brake lights
*Both rear blinkers
*Both rear reverse lights

Not Working:
*Tail Lights (or are they called running lights?  Basically when I have
my car running and driving along, there are no lights on in the rear).

Is this a separate bulb from the brake lights bulb?  I'm going to go to
an autoparts store tomorrow, what would these bulbs be called?  And if
you know the exact model/make/number of these bulbs, I would apprecate
it!!

Thanks.