DTMF

DTMF, or Dual Tone Multi-Frequency signaling, is a method used in telecommunication to recognize keypad presses. When you press a number on a phone, it sends two specific audio tones simultaneously—one from a low-frequency group and another from a high-frequency group—that uniquely identify the digit. These tones are decoded by the phone system to determine which number was pressed. This system allows for quick, reliable dialing and is widely used in landlines, mobile phones, and interactive voice response systems, enabling efficient and accurate communication control.