[isoHunt] FF7

hey I'm dling this file from isohunt bittorrent the file comes with FF7_Disk1.sub
FF7_Disk1.ccd
FF7_Disk1.img
and then disk 2 and 3.... anyhow i want to know what is up with the 2 extra files I've never seen these file extensions before and the image itself won't load and it won't work with demon tools either so does anyone have anyother suggestions? thanks. also im having alot of prob with getting psx emulation cheater to work with epsxe i think i just don't understand how to load it any help is appreciated. thank alot