Game is a structured form of play, usually undertaken for entertainment or fun, and sometimes used as an educational tool. Games are different from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements. However, the distinction is not clear-cut, and many games are also considered to be work (such as professional players of spectator sports or games) or art (such as jigsaw puzzles or games involving an artistic layout such as Mahjong, solitaire, or some video games).

Games are sometimes played purely for enjoyment, sometimes for achievement or reward as well. They can be played alone, in teams, or online; by amateurs or by professionals. The players may have an audience of non-players, such as when people are entertained by watching a chess championship. On the other hand, players in a game may constitute their own audience as they take their turn to play. Often, part of the entertainment for children playing a game is deciding who is part of their audience and who is a player. A toy and a game are not the same. Toys generally allow for unrestricted play whereas games come with present rules.

Game is a structured form of play, usually undertaken for entertainment or fun, and sometimes used as an educational tool. Games are different from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements. However, the distinction is not clear-cut, and many games are also considered to be work ( such as professional players of spectator sports or games) or art (such as jigsaw puzzles or games involving an artistic layout such as Mahjong, solitaire, or some video games).

Key components of games are goals, rules, challenge, and interaction. Games generally involve mental or physical stimulation, and often both. Many games help develop practical skills, serve as a form of exercise, or otherwise perform an educational, simulational, or psychological role. Attested as early as 2600 BC, games are a universal part of human experience and present in all cultures. The Royal Game of Ur, Senet, and Mancala are some of the oldest known games.

Gameplay is the specific way in which players interact with a game, and in particular with video games. Gameplay is the pattern defined through the game rules, connection between player and the game, challenges and overcoming them, plot and player's connection with it. Video game gameplay is distinct from graphics and audio elements. In card games, the equivalent term is play.

Arising alongside video game development in the 1980s, the term gameplay was used solely within the context of video games, though now its popularity has begun to see use in the description of other, more traditional, game forms. Generally, gameplay is considered the overall experience of playing a video game, excluding factors like graphics and sound. Game mechanics, on the other hand, is the sets of rules in a game that are intended to produce an enjoyable gaming experience. Academic discussions tend to favor game mechanics specifically to avoid gameplay since the latter is too vague The word is sometimes misapplied to card games where, however, the usual term is "play" and refers to the way the cards are played out in accordance with the rules (as opposed to other aspects such as dealing or bidding).

Mobile Games is a video game that is typically played on a mobile phone. The term also refers to all games that are played on any portable device, including from mobile phone (feature phone or smartphone), tablet, PDA to handheld game console, portable media player or graphing calculator, with and without network availability. The earliest known game on a mobile phone was a Tetris variant on the Hagenuk MT-2000 device from 1994.

In 1997, Nokia launched Snake. Snake, which was pre-installed in most mobile devices manufactured by Nokia, has since become one of the most played games and is found on more than 350 million devices worldwide. A variant of the Snake game for the Nokia 6110, using the infrared port, was also the first two-player game for mobile phones.

Today, mobile games are usually downloaded from an app store but in some cases are also preloaded in the handheld devices by the OEM or by the mobile operator when purchased, via infrared connection, Bluetooth, or memory card, or side loaded onto the handset with a cable.

Mobile games have been developed to run on a wide variety of platforms and technologies. These include the (today largely defunct) Palm OS, Symbian, Adobe Flash Lite, NTT DoCoMo's DoJa, Sun's Java, Qualcomm's BREW, WIPI, BlackBerry, Nook and early incarnations of Windows Mobile. Today, the most widely supported platforms are Apple's iOS and Google's Android. The mobile version of Microsoft's Windows 10 (formerly Windows Phone) is also actively supported, although in terms of market share remains marginal compared to iOS and Android.

Due to its ease of porting between mobile operating systems and extensive developer community, Unity is one of the most widely used engines used by modern mobile games. Apple provide a number of proprietary technologies (such as Metal) intended to allow developers to make more effective use of their hardware in iOS-native games.

Personal Computer Games, also known as a PC game or computer game, is a type of video game played on a personal computer (PC) rather than a video game console or arcade machine. Its defining characteristics include: more diverse and user-determined gaming hardware and software; and generally greater capacity in input, processing, video and audio output. The uncoordinated nature of the PC game market, and now its lack of physical media, make precisely assessing its size difficult.In 2018, the global PC games market was valued at about $27.7 billion

Home computer games became popular following the video game crash of 1983, leading to the era of the "bedroom coder". In the 1990s, PC games lost mass-market traction to console games, before enjoying a resurgence in the mid-2000s through digital distribution on services such as Steam and GOG.com.

The first generation of computer games were often text-based adventures or interactive fiction, in which the player communicated with the computer by entering commands through a keyboard. An early text-adventure, Adventure, was developed for the PDP-11 minicomputer by Will Crowther in 1976, and expanded by Don Woods in 1977.By the 1980s, personal computers had become powerful enough to run games like Adventure, but by this time, graphics were beginning to become an important factor in games.

Below is a list of some of the most popular game developers today

• Rockstar Games
• Ubisoft
• Electronic Arts
• Naughty Dog
• Square-Enix

Virtual reality game or VR game is a video game played on virtual reality (VR) hardware. Most VR games are based on player immersion, typically through head-mounted display unit or headset and one or more controllers. The headset typically provides two stereoscopic displays in front of the user's eyes to simulate a 3D space.

The video game industry made early attempts at VR in the 1980s, most notably with Mattel's Power Glove and Nintendo's Virtual Boy. With the introduction of the first consumer-ready VR product, the Oculus Rift, in 2013, VR games soon followed, including existing games adapted for the VR hardware, and new games designed directly for VR. While VR hardware and games grew modestly for the remainder of the 2010s, Half-Life: Alyx, a full VR game developed by Valve, was considered the killer application for VR games.

In its current meaning, "virtual reality" generally has been taken to creating immersion and presence with the player by creating a new visual stimulus (through a VR headset for example) that obscures to real world view. This definition distinguishes VR from augmented reality where additional visual information is added atop the real world view. A broader definition of virtual reality can be taken to be any application that replaces one or more of the human senses with a virtual one.Thus, games featuring any alternative control scheme compared to a typical game controller or keyboard-and-mouse system could be considered as a virtual reality game, where the sense of touch of these traditional controls is replaced with a novel scheme. Such games would include those with alternate peripherals such as Dance Dance Revolution and Guitar Hero, or games featuring motion controls such as many Wii-based games.However, with the expansion of VR hardware in the 2010s, the use of "virtual reality" to include these types of games has been deprecated.

Research into virtual reality (VR) hardware and software started as early as 1968 by Ivan Sutherland and his student Bob Sproull , but most equipment was too expensive for consumer use, and its use for games was limited. The first VR head mounted display that was connected to a computer. In the late 1980s, Jaron Lanier and Thomas G. Zimmerman, former programmers for Atari, Inc., began developing hardware under the name VPL Research, with Lanier coining the term "virtual reality" for their products. One of VPL's products was the VPL DataGlove, a glove that sensed the user's finger movement and translated it into computer input. The idea inspired engineers at Abrams/Gentile Entertainment (AGE) to work with Mattel and Nintendo to build a low-cost version of the DataGlove to work with the Nintendo Entertainment System (NES), omitting much of the technical sophistication and movement sensitivity of the DataGlove as to achieve a reasonable consumer cost. The Power Glove was released in 1989. The games Super Glove Ball and Bad Street Brawler were specifically designed to use the Power Glove, while other NES games could be played using the Power Glove by mapping its output to various controls. About one million Power Glove units were sold before Mattel discontinued it in 1990. Its low cost compared to the DataGlove and other similar gloves led academics to buy the unit for their own research.