A PS2 ISO is a digital copy of a PlayStation 2 game, ripped directly from the original disc. In the case of the Mortal Kombat Arcade Kollection, a PS2 ISO would contain the entire game, including all its contents, such as the three classic Mortal Kombat games: Mortal Kombat (1992), Mortal Kombat II (1993), and Mortal Kombat 3 (1995). This format allows players to experience the games without the need for the physical disc, and often with improved performance and compatibility.