A tape deck is a machine that plays and records sound on magnetic tape. Before digital music, people used tape decks to listen to cassette tapes, which were small plastic rectangles containing thin magnetic tape wound around two spools.

When you pressed play on a tape deck, the tape would move past a special magnetic head that could “read” the sounds stored on the tape and send them to speakers. If you pressed record, the tape deck would capture sounds from a microphone or radio and store them magnetically on the tape. You could make your own mix tapes by recording your favorite songs from the radio, or record yourself singing.

Tape decks were everywhere in the 1970s and 1980s: in cars, home stereo systems, and boomboxes. Unlike records, you could take cassette tapes anywhere and play them in portable devices like a Walkman. The technology seems primitive now compared to streaming music from your phone, but tape decks represented real freedom at the time: you could finally take your music collection with you wherever you went.

The phrase tape deck specifically refers to the mechanical player itself, as opposed to the cassette tape you inserted into it.