A video game console is an interactive entertainment computer or electronic device that produces a video display signal which can be used with a display device (a television, monitor, etc.) to display a video game. The term "video game console" is used to distinguish a machine designed for consumers to buy and use solely for playing video games from a personal computer, which has many other functions, or arcade machines, which are designed for businesses that buy and then charge others to play.
The "video" in "video game console is a thing that can play games" traditionally refers to a raster display device. However, with the popular use of the term "video game" the term now implies all display types and formats. The term "console" is used in the user manuals of several early video game systems. Its use, however, is not synonymous with "video game system" or the same as its modern usage. It refers to a specific part of the video game system. The Atari 2600, NES, and other consoles from those decades were called "video game systems" at the time. 
The first company to use the term "console" to officially refer to its video game system was Fairchild with the Video Entertainment System (VES) in 1976. Since then, definition has widened to include entire systems, as well as to describe alternate platforms such as handheld game consoles, TV games, and multimedia devices. In common usage a "console" is a specialized electronic device that connects to a standard television set or composite video monitor. A "handheld" gaming device is a self-contained electronic device that is portable and can be held in a user's hands.
a power supply converts 100-240 volt AC utility power into direct current (DC) at the voltages needed by the electronics.
Most video game consoles have their programs stored on external media. They are the ROM of consoles.
Some video game consoles, like the PlayStation and the Nintendo GameCube have memory cards to save, load, and delete files. Though recent consoles such as the Xbox, Xbox 360, PlayStation 3, and Wii all have – or can have installed – hard drives/internal memory which save the data on the console itself. Memory cards are like flash drives for consoles.
See also: History of video games.
See main article: History of video game consoles (first generation).
Although the first computer games appeared in the 50s, they used vector displays, not video. It was not until 1972 that Magnavox released the first home video game console, the Magnavox Odyssey, invented by Ralph H. Baer. The Odyssey was initially only moderately successful, and it was not until Atari's arcade game Pong popularized video games, that the public began to take more notice of the emerging industry. By the autumn of 1975 Magnavox, bowing to the popularity of Pong, cancelled the Odyssey and released a scaled down console that only played Pong and hockey, the Odyssey 100. A second "higher end" console, the Odyssey 200, was released with the 100 and added onscreen scoring, up to 4 players, and a third game – Smash. Almost simultaneously released with Atari's own home Pong console through Sears, these consoles jump-started the consumer market. As with the arcade market, the home market was soon flooded by dedicated consoles that played simple pong and pong-derived games.
See main article: History of video game consoles (second generation). Fairchild released the Fairchild Video Entertainment System (VES) in 1976. While there had been previous game consoles that used cartridges, either the cartridges had no information and served the same function as flipping switches (the Odyssey) or the console itself was empty and the cartridge contained all of the game components. The VES, however, contained a programmable microprocessor so its cartridges only needed a single ROM chip to store microprocessor instructions.
RCA and Atari soon released their own cartridge-based consoles.
In 1977, manufacturers of older, obsolete consoles sold their systems at a loss to clear stock, creating a glut in the market and causing Fairchild and RCA to abandon their game consoles. Only Atari and Magnavox stayed in the home console market.
The VES continued to be sold at a profit after the 1977 crash, and both Bally (with their Home Library Computer in 1977) and Magnavox (with the Odyssey 2 in 1978) brought their own programmable cartridge-based consoles to the market. However, it wasn't until Atari released a conversion of the arcade hit Space Invaders in 1980 that the home console industry was completely revived. Many consumers bought an Atari just for Space Invaders. Space Invaders' unprecedented success started the trend of console manufacturers trying to get exclusive rights to arcade titles, and the trend of advertisements for game consoles claiming to bring the arcade experience home.
Throughout the early 1980s, other companies released video game consoles of their own. Many of the video game systems were technically superior to the Atari 2600, and marketed as improvements over the Atari 2600. However, Atari dominated the console market in the early 1980s.
See main article: Video game crash of 1983.
In 1983, the video game business suffered a much more severe crash. A flood of consoles, of low quality video games by smaller companies (especially for the 2600), industry leader Atari hyping games such as E.T. that were poorly received, and a growing number of home computer users caused consumers and retailers to lose faith and interest in video game consoles. Most video game companies filed for bankruptcy, or moved into other industries, abandoning their game consoles. Mattel Electronics sold the rights for its Intellivision system to the INTV Corporation, who continued to produce Intellivision consoles and develop new games for the Intellivision until 1991. All other North American game consoles were discontinued by 1984.
See main article: History of video game consoles (third generation).
In 1983, Nintendo released the Famicom in Japan. Like the ColecoVision, the Famicom supported high-resolution sprites and tiled backgrounds, but with more colors. This allowed Famicom games to be longer and have more detailed graphics. Nintendo brought their Famicom over to the US in the form of the Nintendo Entertainment System (NES) in 1985. In the US, video games were seen as a fad that had already passed. To distinguish its product from older video game consoles, Nintendo used a front-loading cartridge port similar to a VCR on the NES, packaged the NES with a Super Mario Brothers game and a light gun (the Zapper), and originally advertised it as a toy. The plastic "robot" (R.O.B.) was also sold as an individual purchase item and in some cases packaged with the NES system.
Like Space Invaders for the 2600, Nintendo found its breakout hit game in Super Mario Bros. Nintendo's success revived the video game industry and new consoles were soon introduced in the following years to compete with the NES.
Sega's Master System was intended to compete with the NES, but never gained any significant market share in the US and was barely profitable. It fared notably better in PAL territories, especially Brazil.
See main article: History of video game consoles (fourth generation). Sega regained market share by releasing its next-generation console, the Sega Mega Drive, which was released in Japan on October 29, 1988, in the U.S. in August 1989 (renamed as the Sega Genesis) and in Europe in 1990, two years before Nintendo could release the Super Nintendo Entertainment System (SNES).
Sega extended the Mega Drive with the Mega CD/Sega CD, to provide increased storage space for multimedia-based games that were then in vogue among the development community. Later, Sega released the 32X, which added some of the polygon-processing functionality common in fifth-generation machines. However, the peripheral was a commercial failure due to lack of software support, with developers more keen to concentrate on more powerful machines, with a wider user base, such as the Saturn that followed shortly after.
See main article: History of video game consoles (fifth generation).
The first fifth generation consoles were the Atari Jaguar and the 3DO. Both of these systems were much more powerful than the Super Nintendo Entertainment System (SNES) or Mega Drive (known as Genesis in North America); they were better at rendering polygons, could display more onscreen colors, and the 3DO used CDs that contained far more information than cartridges and were cheaper to produce. Neither of these consoles were serious threats to Sega or Nintendo, though. The 3DO cost more than the SNES and Genesis combined, and the Jaguar was extremely difficult to program for, leading to a lack of games that used its extra power. Both consoles would be discontinued in 1996.
Nintendo released games like Donkey Kong Country that could display a wide range of tones (something common in fifth generation games) by limiting the number of hues onscreen, and games like Star Fox that used an extra chip inside of the cartridge to display polygon graphics. Sega followed suit, releasing Vectorman and Virtua Racing (the latter of which used the Sega Virtua Processor).
It was not until Sega's Saturn, Sony's PlayStation, and the Nintendo 64 were released that fifth generation consoles started to become popular. The Saturn and PlayStation used CDs to store games, while the N64 used cartridges. All three cost far less than the 3DO, and were easier to program than the Jaguar. The Saturn also had 2D sprite handling power on par with the Neo-Geo.
See main article: History of video game consoles (sixth generation). This generation saw a move towards PC-like architectures in gaming consoles, as well as a shift towards using DVDs for game media. This brought games that were both longer and more visually appealing. Furthermore, this generation also saw experimentation with online console gaming and implementing both flash and hard drive storage for game data.
See main article: History of video game consoles (seventh generation). The features introduced in this generation include the support of new disc formats: Blu-ray Disc, utilized by the PlayStation 3, and HD DVD supported by the Xbox 360 via an optional accessory, this later failed as the format war closed. Another new technology is to use of motion as input (as demonstrated by the Wii and the PS3), and IR tracking (as implemented on the Wii). Also, all seventh generation consoles support standard wireless controllers.
Each new generation of console hardware made use of the rapid development of processing technology. Newer machines could output a greater range of colors, more sprites, and introduced graphical technologies such as scaling, and vector graphics. One way this increase in processing power was conveyed to consumers was through the measurement of "bits". The TurboGrafx-16, Sega Genesis, and SNES were among the first consoles to advertise the fact that they contained 16-bit processors. This fourth generation of console hardware was often referred to as the 16-bit era, and the previous generation as the 8-bit.
The bit-value of a console referred to the word length of a console's processor (although the value was sometimes misused, for example the TurboGrafx 16 had only an 8-bit CPU, and the Genesis/Mega Drive had the 16/32-bit Motorola 68000, but both had a 16-bit dedicated graphics processor). As the graphical performance of console hardware is dependent on many factors, using bits was a crude way to gauge a console's overall ability, but served better to distinguish between generations.
Game cartridges consist of a printed circuit board housed inside of a plastic casing, with a connector allowing the device to interface with the console. The circuit board can contain a wide variety of components. All cartridge games contain at the minimum, read only memory with the software written on it. Many cartridges also carry components that increase the original console's power, such as extra RAM or a coprocessor. Components can also be added to extend the original hardware's functionality (such as gyroscopes, rumble packs, tilt-sensors, light sensors, etc.); this is more common on handheld consoles where the user does not interact with the game through a separate video game controller.
Cartridges were the first external media to be used with home consoles and remained the most common until 1995 continued improvements in capacity (Nintendo 64 being the last mainstream game console to use cartridges). Nevertheless, the relatively high manufacturing costs saw them completely replaced by optical media for home consoles by the early 21st century, although they are still in use in some handheld video game consoles.
Due to the aforementioned capabilities of cartridges such as more memory and coprocessors, those factors make it harder to reverse engineer consoles to be used on emulators.
See also: Smart Card. Several consoles such as the Sega Master System and the TurboGrafx-16 have used different types of smart cards as an external medium. These cards function similar to simple cartridges. Information is stored on a chip that is housed in plastic. Cards are more compact and simpler than cartridges, though. This makes them cheaper to produce and smaller, but limits what can be done with them. Cards cannot hold extra components, and common cartridge techniques like bank switching (a technique used create very large games) were impossible to miniaturize into a card in the late 1980s. 
Compact Discs reduced much of the need for cards. Optical Discs can hold more information than cards, and are cheaper to produce. The Nintendo Gamecube and the Playstation 2 use memory cards for storage, but the Nintendo DS is the only modern system to use cards for game distribution. Nintendo has long used cartridges with their Game Boy line of hand held consoles because of their durability, small size and low battery consumption. Nintendo switched to cards for the DS, because advances in memory technology made putting extra memory on the cartridge unnecessary.
Home computers have long used magnetic storage devices. Both tape drives and floppy disk drives were common on early microcomputers. Their popularity is in large part because a tape drive or disk drive can write to any material it can read. However, magnetic media is volatile and can be more easily damaged than game cartridges or optical discs.
Among the first consoles to use magnetic media were the Bally Astrocade and APF-M1000, both of which could use cassette tapes through expansions. In Bally's case, this allowed the console to see new game development even after Bally dropped support for it. While magnetic media remained limited in use as a primary form of distribution, two popular subsequent consoles also had expansions available to allow them to use this format. The Starpath Supercharger can load Atari 2600 games from audio cassettes; Starpath used it to cheaply distribute their own games from 1982 to 1984 and today it is used by many programmers to test, distribute, and play homebrew software. The Famicom Disk System was released by Nintendo in 1985 for the Japanese market. Nintendo sold the disks cheaply and sold vending machines where customers could have new games written to their disks up to 500 times.
In the mid-1990s, various manufacturers shifted to optical media, specifically CD-ROM, for games. Although they were slower at loading game data than the cartridges available at that time, they were significantly cheaper to manufacture and had a larger capacity than the existing cartridge technology. By the early 21st century, all of the major home consoles used optical media, usually DVD-ROM or similar disks, which are widely replacing CD-ROM for data storage. The PlayStation 3 system uses even higher-capacity Blu-ray optical discs for games and movies while the Xbox 360 formerly used HD DVDs in the form of an external USB player add-on for movies, before it was discontinued. Microsoft still however, supports those who bought the accessory.
All three seventh generation consoles (the PlayStation 3, Wii, and Xbox 360) offer some kind of Internet games distribution service, allowing users to download games for a fee onto some form of non-volatile storage, typically a hard disk or flash memory. Recently the console manufacturers have been taking full advantage of Internet distribution with arcade games, television shows and film trailers being available.