GRP, StarCraft Graphics Group File (.grp)
The GRP Misc file format
GRP files belong to the big category of game files. They are product of a computer game and serve a distinct function within the game's set up. The most common association of GRP files comes from Blizzard's StarCraft computer game. The file was used to group a collection of images used for items in the game like weapons, units, but also spells and other graphics.
Technical details of GRP files
More precisely, the images contained in the GRP file are a collection of frame images. One game object can consist of only few or over 100 frames, making for small as well as very large GRP files. GRP files can be interpreted by StarCraft, but it is possible to edit them with other editing software.