Concept art is a piece of art that has been created for games, either to go in the game or be used mearly as a game poster.
Concept artists create their artistic views on characters, weapons or vehicles that they are either given or are told to do by the directors of the game. They also create settings/scenes for games based on designs, real scenes or sci-fi designs that others or themselves have created. Concept artists are a vital essence in the game making process; they create the main characters, the ones that are shown alot, and if the main characters dont look any good then some gamers can be put off buying the game.
3D modellers use the concept art to create the designs made by the concept artists and the 3D modellers can also change/ alter how the concept artist has made that design. Big companies tend to hire experianced concept artists and 3D modellers. Concept art is also used in the making of the games packaging. The cover of the packaging is made using imaging software as it is best for getting the best colours and the best tools to edit and create the cover i.e. uses the concept artists design to make the cover for the game using Adobe photoshop.
2D sprites are commonly used in handheld games systems. They use pixels to be created and are placed into a game when they are finished and have enough pixels to make a recognisable abstract image. A popular game that uses this is Pokemon. 3D sprites are made the same way as 2D sprites, yet before they are placed into a game, the characters and scenery are distorted at an angle to give them a 3D viewpoint. A recent game that uses this is Square Enix's, Dragon quest IX.