A plugin also adds compatibility to put Playstation 2 games in the CD or DVD drive and play them from there. Those games can be in all image formats like iso, img or bin. Besides the Bios you also need a game obviously before you can play Playstation 2 games. Note that it is not legal to download the bios from these sites though.
Iknow that most P2P networks have those files available as well. It is possible to use tools to extract the bios of your own Playstation 2 but that requires at least some technical knowledge to get started. The developers can't supply one because they would infringe on Sony's copyright.
The first is that you do need a Playstation 2 bios file. There are two prerequisites that are a big hurdle for many users. Many regard the Pcsx2 emulator as the best Playstation 2 emulator in existence and I have to say that it really does an awesome job as long as your computer is fast enough to handle the emulation.
