Instead of referring to a particular brand-name console, Plug and Play is a general term that applies to self-contained video game devices that connect directly to a television and do not require any additional software or equipment. The game software is stored inside the Plug and Play device, along with the computing and graphics hardware, so no separate game cartridges or discs are involved. Users need only plug the unit into their television sets in order to play the included games.
The very earliest home consoles can be considered Plug and Play, including living room Pong machines and light gun games. Because televisions of the era do not have RCA input jacks, these early Plug and Play consoles connect to the antenna port of the TV set, using a "Radio Frequency Switch" converter. It wasn't until after the 1977 introduction of the influential Atari Video Computer System that most home game consoles began to be designed to run sold-separately software.
Plug and Play games became notably popular again in the first decade of 2000, when a great variety of affordable stand-alone devices were quickly brought to market by companies such as JAKKS Pacific and Radica. With miniaturization and other technological advances, well-known games created 15 or 20 years earlier, for expensive home console systems and commercial arcade machines, could now be programmed into a small handheld device that takes only a few seconds to connect to (and disconnect from) almost any TV.
In this trend, many newly designed "16-bit style" games, often featuring licensed characters, were also released on Plug and Play devices. The relative ease of programming and production allowed manufacturers to quickly create new games based on ephemerally popular television shows, movies, and toy lines. These Plug and Play devices offer an inexpensive, portable alternative to more sophisticated console systems. Such modern Plug and Play devices remain popular, although the rise of high-definition televisions has tended to emphasize their limited graphical capabilities. ~ T.J. Deci, All Game Guide