Archive file

An archive file is a file that is composed of one or more files along with metadata, such as file names, sizes and offsets within the archive. They are used for faster access to file contents by game, as well as compression (in some cases) to safe space on the storage medium. GTA makes use of various archive file formats for different purposes.

GTA III, Vice City and San Andreas:
 * IMG archives are used for all game assets except audio
 * SFX files and various audio streams

GTA IV:
 * new IMG archive format
 * RPF archives