Pixel Art
Pixel Art is a form of digital art, this art style is created using raster graphic software such as photoshop etc... where you can create images pixel by pixel.
Before 3D games were released near enough every game had pixel art in them as they were very dominant. You can recognize pixel art by the blocked effect. The way you can achieve this effect is by creating an image using the pixels however, due to the size of the pixels leave you limited on your ideas.
Concept Art
Concept art is where you use illustration to develop your idea for a video game. This could be used in creating the setting, characters or objects around the level. However, to use this style of art is quite a lengthy process.
Texture Art
Texture art is the art of creating assets for games. These assets are then used to create 3D models that are photographic images.
Background Graphics
Background Graphics are used in the background of games also known as the interface. They are there to help put the player in the mindset of the games setting however, doesn't effect the gameplay directly.
Print Media Graphics
Print Media Graphics consist of products such as; promotional objects like, hoodies, cups, posters etc... and box art. This style of art is anything graphical work that is in print form.