It was invented in 1876 by Alexander Graham Bell , a teacher of the deaf. Parts of the telephone include the jack, electronics box, dial, hand-set and bell. A telephone has to do many things. All this is done inside the telephone electronics box. The electronics are made up of different electrical circuits, which include capacitors, resistors and inductors.
Many modern telephones have a buzzer instead of a bell.
But the purpose is the same. When a signal comes into your telephone over the wires, the bell rings to tell you that someone has called your number. The dial tone indicates that the exchange is ready to accept your call. As you release the dial after each digit of a phone number, the current is turned off and on from one to 10 times, depending on the digit. For example, for the number 3, the electric current is interrupted three times.