Highly compressed games refer to game files that have been reduced in size using various compression algorithms and techniques. This allows for smaller file sizes, making it easier to store and share games online. In the context of PS2 games, highly compressed games often refer to ISO files that have been compressed to reduce their size.
Gran Turismo 4 (original ISO = 5.7GB) → Highly compressed .7z = 1.2GB. i--- Ps2 Highly Compressed Games Iso