What is Ringtone ?

A ringtone or ring tone is the sound made by a telephone to indicate an incoming call. The term, however, is most often used to refer to the customizable sounds available on mobile phones. This facility was originally provided so that people would be able to determine when their phone was ringing when in the company of other mobile phone owners.[citation needed]

A phone only rings when a special "ringing signal" is sent to it. For landline telephones, the ringing signal is a 90-volt, 20-hertz, AC wave generated by the switch to which the telephone is connected. For mobile phones, the ringing signal is a specific radio-frequency signal.

A telephone ring is the sound generated when an incoming telephone call is received. The term originated from the fact that telephones notified the user to an incoming call by repeatedly striking a bell or bells, producing a ringing sound.

This "Magneto" bell system is still in widespread use; newer telephones use electronic sounders to produce other noises, but the term "ring" is still used. The ringing signal sent to a customer's telephone is AC at around 90 volts (at 20 hertz in North America, because of the use of 60 Hz mains; other regions with 50 Hz mains use 25 Hz); modern telephones electronically produce a warbling or chirping sound. The signal is sent for every ring and allows phone operators to provide several services with different kinds of rings (for example, rings with a shorter interval between them might be used to signal a call from a given number). When a home phone rings, it may carry Caller ID information and present it on a screen.