Ive been given 12 CD discs and told that i will WANT these.
6 discs are labelled MAME ROMS
6 discs are labelleds MAME CHD.

Opening them up the ROMS discs are chock full of zip files in alphabetical order.. i cant actually read the files.. just what they are.
Looks to me like ive just been handed several hundred ROM images for MAME games... does anyone know anything about these discs.
The CHD files i have no idea what they are... whats a CHD file?

Instructions on READ ME file just tell me to copy files in their entirety to my MAME directory.

Im so arcade ignorant... but anyone know if its to play games on my comp or to replace game ROMs??

Some games such as Killer Instinct use a hard drive to run the game.
A CHD file is information or image from the hard drive of that particular game.
The associated ROMS will not work without the CHD files