Headphones are a pair of small speakers that you wear on or over your ears to listen to music, videos, or other audio privately. Unlike regular speakers that fill a room with sound, headphones direct sound straight into your ears so only you can hear what's playing.

The basic design hasn't changed much since they were invented: two earpieces connected by a band that goes over your head, or smaller versions called earbuds that tuck directly into your ears. When you plug headphones into a phone, computer, or music player, electrical signals travel through the wire (or wirelessly through Bluetooth) and get converted into sound waves by tiny speakers inside each earpiece.

Headphones let you listen to your favorite podcast during a long car ride without disturbing your sister, or practice piano on an electric keyboard late at night without waking your parents. Students use them in computer labs so thirty kids can all work on different assignments without creating chaos. Musicians wear professional headphones in recording studios to hear exactly how their music sounds while they're performing.

People often say headphones (plural) even when talking about one set, since they come as a pair.