You need a PSP. Install a tool like UMDumper or ISO Tool .
There is a debate within the archiving community regarding the "best" format. psp cso roms archive
These are preservation databases, not download sites. However, DAT files from Redump allow you to verify that your personal is complete and uncorrupted. Many private torrents use these DATs to distribute 1:1 verified CSO collections. You need a PSP