The following is a list providing an overview of all the different tape cartridge and cassette formats that use magnetic tape. Both "cassette" and "cartridge" refer to a small plastic unit containing a length of magnetic tape on at least one reel. The unit may contain a second "take-up" reel or interoperate with such a reel in an associated tape drive. At least 142 distinct types have been known to exist.
The phrase cassette tape is ambiguous in that there is no common dictionary definition so depending upon usage it has many different meanings, as for example any one the one of 106 different types of audio cassettes, video cassettes or data cassettes listed at The Museum of Obsolete Media.
