"Touch-Tone" refers to a system of dialing telephone numbers using buttons instead of a rotary dial. Each button produces a specific sound, or tone, when pressed, allowing the phone to send signals to the telephone network. This technology made it easier and faster to connect calls, as users could simply press the numbers they needed. Introduced in the 1960s, Touch-Tone phones quickly became popular, replacing older models. The tones are generated using a method called Dual-Tone Multi-Frequency (DTMF), which combines two different frequencies for each button. This innovation paved the way for modern telecommunication systems and features like voicemail and automated menus.