Compact Cassette in the context of "Mobile DJs"

Walkman (Japanese: ウォークマン, Hepburn: Wōkuman) is a brand of portable audio players manufactured by Sony since 1979. It was originally introduced as a portable cassette player and later expanded to include a range of portable audio products. Since 2011, the brand has referred exclusively to digital flash memory players.

The Walkman became widely popular during the 1980s for its portable design and private listening experience. It influenced popular culture by promoting individualized music consumption and supporting activities such as aerobics. Its widespread use gave rise to the "Walkman effect", a term describing how portable music devices and headphones allow listeners to control their sonic environment. In 1986, "Walkman" was added to the Oxford English Dictionary, and in some markets the term became a genericized trademark for portable audio players. The Walkman also contributed to the widespread adoption of the Compact Cassette format, which surpassed vinyl record sales in 1983. Sony sold approximately 220 million cassette-based Walkman units before ending production in 2010.

A cassette is a small plastic unit containing a length of magnetic tape on two reels. The design was created to replicate the way a reel-to-reel machine works with tape moving from one reel to another while being read by a tape head. The design was first made for audio formats but then expanded into video and data storage.

As of 2025, although the cassette format is no longer used for video or data storage, it is still used as an audio format with many consumers still purchasing new album releases on cassette.

The Microcassette (often written generically as microcassette) is an analog audio cassette storage format, introduced by Olympus in 1969.

It has the same width of magnetic tape as the Compact Cassette but in a cassette roughly one quarter the size. By using thinner tape and half or a quarter the tape speed, microcassettes can offer comparable recording time to the compact cassette but in a smaller package.

Digital Audio Tape (DAT or R-DAT) is a discontinued digital recording and playback medium developed by Sony and introduced in 1987. In appearance it is similar to a Compact Cassette, using 3.81 mm / 0.15" (commonly referred to as 4 mm) magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. The recording is digital rather than analog. DAT can record at sampling rates equal to, as well as higher and lower than a CD (44.1, 48, or 32 kHz sampling rate respectively) at 16 bits quantization. If a comparable digital source is copied without returning to the analogue domain, then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non-Hi-MD MiniDisc, both of which use a lossy data-reduction system.

Similar to most formats of videocassette, a DAT cassette may only be recorded and played in one direction, unlike an analog compact audio cassette. Many DAT recorders had the capability to embed program numbers and IDs into the recording which can be used to select an individual track like on a CD player.