1793, "little box," from French cassette, from Middle French casset, diminutive of Old North French casse "box" (see case (n.2)). Meaning "magnetic tape recorder cartridge" is from 1960.
in audio and video recording, flat, rectangular container made of plastic or lightweight metal that holds magnetic tape for audio or video recording and replay. A tape cassette is designed so that it can be inserted in a recorder and used immediately; it eliminates the need to thread a portion of the tape manually before starting the recorder. In a cassette the tape begins on a feed reel at one side and moves along guides through the record-playback mechanism, after which it passes on to the take-up reel on the opposite side.