What is the grinding noise?

My car is making a grinding noise from the rear when I take off or come to a stop. What's happening?

• The other day I was pulling out of a store and the car wouldn't move for a second. I pumped the brakes and the car was mobile and moving again. It was making a grinding noise every time I was starting and stopping, but I found pumping the brakes makes the grinding almost go away altogether when I come to a stop. I did call my mechanic and left a message, but payday isn't until Friday. I thought I just may need rear brake pads, but since pumping them makes the grinding noise stop, I'm perplexed. What may be happening and what would the danger level be driving it until Friday?

• Answer:

  Don't know what type of car but sounds like [caliber if you have rear disks or piston if rear drums] are bad and now you need rotor or drum along with new brakes.