He explains that the PlayStation 2 couldn’t keep the entire open-world game map in its tiny 32 MB of RAM. Instead, models had to be streamed from the DVD drive as the player moved around the world.

large-scale games on DVD discs,” referring to the PlayStation 2’s innovative disc drive. The launch of the PS2 was helped by a strong lineup of next-generation (for the time) software ...

The DVD player in the console made it accessible ... According to Guinness World Records, 157.68 million people have owned a PlayStation 2 in their lifetime. That's ahead of the 154.90 million ...