This 200 amp meter panel has a series of breakers that operate the different outlets in the house. It is helpful to identify which breaker serves which outlets (i.e., kitchen, bathroom, laundry) so that the breaker can be turned off or reset if there is a problem. The top breaker in this picture is the main breaker. If this were a 100 amp panel, all of the breakers would be located directly below the meter.