• Tone Generation: DTMF works by generating two tones simultaneously when a button on a keypad is pressed. Each number key on a telephone keypad is assigned a specific frequency pair – one low-frequency tone and one high-frequency tone.

• Use in Telecommunication: DTMF is primarily used for dialing telephone numbers and navigating interactive voice response (IVR) systems, commonly encountered in customer service call menus.

• Replacement of Pulse Dialing: DTMF replaced the older pulse dialing technology, offering faster and more reliable service. It became the standard for push-button telephones and mobile phones.

• Technical Advantages: The use of two tones for each key ensures that the system is more resistant to line noise and can operate reliably over long distances.

DTMF's introduction marked a significant advancement in telecommunication technology, enabling more efficient and effective telephone and data communication.