Touch-tone phones are a type of telephone that use a keypad with buttons to dial numbers. Each button corresponds to a specific number or symbol, and pressing a button sends a unique tone to the phone network. This technology replaced older rotary dial phones, making it faster and easier to make calls. Introduced in the 1960s, touch-tone phones became popular for their convenience. They allowed users to quickly enter phone numbers and access services like voicemail and automated systems. Today, while most people use cell phones or smartphones, touch-tone technology remains a fundamental part of modern telecommunications.