A phonograph is a machine that plays sound recordings by using a needle to read the grooves carved into a spinning disc or cylinder. When Thomas Edison invented the phonograph in 1877, it was the first device ever to both record and play back sound, something people had never imagined possible.

Here's how it works: sound waves create vibrations that get carved into grooves on a record (a flat disc made of vinyl or shellac). When you want to hear the recording, you place the record on the phonograph's turntable, which spins it around. A small needle, called a stylus, sits in the groove and vibrates as it follows the tiny bumps and dips. These vibrations travel through the phonograph's arm to a speaker or horn, which amplifies them back into sound you can hear.

Before phonographs, the only way to hear music was to have someone perform it live right in front of you. The phonograph changed everything: suddenly, you could listen to your favorite singer or orchestra whenever you wanted, even if they were thousands of miles away. People also call phonographs record players or turntables, and while most people today listen to music digitally, vinyl records and phonographs are still beloved by music enthusiasts who appreciate their warm, rich sound quality.