what is the difference between a brushless rc petrol car and one without ?

okay so im thinking of buying a rc nirto petrol car and i dont know what the brushless things is and what it does, is it better to buy one with it or without ? ¬_¬

nitro rc cars dont have brushes at all its only electric rc cars which have them, they are inside the motor of an electric rc car so that the car can go fast, (electromagnet)