That thing on the wall in the basement, garage or utility room that the big electrical cable from the street comes into, and then is fed to lots of little circuit breakers (or fuses if your house is old) and then powers the circuits in your house.

Your electrical panel is important, and there shouldn't be rust on it, the breakers should be solidly attached, and most importantly, it shouldn't be buzzing. Also, if it is buzzing, the buzzing shouldn't be in sync with the flickering of the lights in your home. If any of this is happening, seek out the services of a licensed electrician.