There are two kinds of electrical charge—positive and negative. An object that gains electrons has a negative charge. An object that loses electrons has a positive charge. Two charges of the same kind push each other apart. We say that they repel each other. Two charges of different kinds pull each other together. We say that they attract each other.
Try combing your hair quickly, and then holding the comb near your hair. Your hair stands on end! When you combed your hair, electrons rubbed off the hair onto the comb. This set up an electrical charge. The comb gained extra electrons and so had a negative charge. Your hair lost some electrons and so had a positive charge. Your hair rose towards the comb because the positive and negative charges attracted each other.
