Brake warning light

[grammat]

My brake warning light went on yesterday.
What does that mean? Does the indicator light come on when the brakes are getting so low or that the brake fluid level is low?
I know very little about cars and don't have the money to go to a dealer.

[bpage020602]

I dont know why your brake light is on but make sure the e brake is not pushed and Check your brake fluid, make sure its not low then if its none of those then it is probaly your brakes. If its not your brakes then maybe the sensor got messed up. I'm not to sure. Good luck though.