Alternatively referred to as a phone, a telephone is a device that converts analog audio into electrical signals that can be transferred to other telephone users. Originally it was an electric tool transmitting analogue speech along wires. Now it is an electronic tool sending digital signals on wires or radio transmission.
There are four categories of phones: the classic corded telephone (which could utilize a rotary dial or have buttons), the cordless or wirelessphone, the standard cell phone, and the smartphone. Today, the landlineversion of the telephone is widely being replaced by cell phones and smartphones as they are much more convenient and service prices have come down drastically.