A cassette deck is a type of tape machine for playing and recording audio cassettes that does not have a built-in power amplifier or speakers, and serves primarily as a transport. It can be a part of an automotive entertainment system, a part of a portable mini system or a part of a home component system. In the latter case it is also called a component cassette deck or just a component deck.
A "tape recorder" is a more generic term to identify a device that usually has a self-contained power amplifier and either has a built-in speaker or comes packaged with one.
The first consumer tape recorder to employ a tape reel permanently housed in a small removable cartridge was the RCA tape cartridge, which appeared in 1958 as a predecessor to the cassette format. At that time, reel to reel recorders and players were commonly used by enthusiasts, but required large individual reels and tapes which had to be threaded by hand, making them less-accessib