This is all taken from the web:
Warning Sign Indicators
Squealing A high pitched noise that occurs regularly when the brakes are applied
Fading A nonresponsive or "sinking" brake that indicates a leak in the system
Pulling Vehicle pulls to one side when the brake is applied indicating uneven wearing of the brake pads or foreign matter in the brake fluid
Grinding or growling A loud metallic sound indicating pads that are completely worn down and are scratching or scoring the rotors
Vibration A pulsation felt when the brake is applied; if felt in the pedal and steering wheel, it is the front brakes; if felt in the seat and pedal, it is the rear brakes
These are the worst rotor pictures I could find (except the explanation one). Have your mechanic show you the issue. And always get a second opinion if you are not sure.
Warning Sign Indicators
Squealing A high pitched noise that occurs regularly when the brakes are applied
Fading A nonresponsive or "sinking" brake that indicates a leak in the system
Pulling Vehicle pulls to one side when the brake is applied indicating uneven wearing of the brake pads or foreign matter in the brake fluid
Grinding or growling A loud metallic sound indicating pads that are completely worn down and are scratching or scoring the rotors
Vibration A pulsation felt when the brake is applied; if felt in the pedal and steering wheel, it is the front brakes; if felt in the seat and pedal, it is the rear brakes




These are the worst rotor pictures I could find (except the explanation one). Have your mechanic show you the issue. And always get a second opinion if you are not sure.