Different ISO file extensions?

I just started using a PSX emulator (ePSXe 1.8), and I'm noticing when I download ISOs, they're coming in a folder with several files, each with a different extension. I only have a few ISOs so far, and I've come across .bin, .cue, .ccd, .img, & .sub

Can someone explain the difference between these files? Is there a certain one you should use?

I should mention I'm an accuracy whore, and I've also read something that says there's a program called Deamons Tools, and it could make the EMUs more accurate if you run the ISOs from that. Is that correct?

I can't discern any noticeable difference from reading from Daemon Tools and just the ISO. Im not going to pretend that I know a whole bunch about differences between ISO formats, but there seems to be a difference in the size of data, so maybe some compression differences? Im sure someone with more knowledge with show up and explain more than I.

An iso is not to be confused with a disk image by any means. There are lots of algorithms in ripping a disc. The bin cue mainly came out of nowhere for psx games. The bin is a binary dump of the disc and the cue tells it were the music data starts. Its made by cdr-win.

The .ccd, .img, & .sub are CloneCD images. Again the img is the dump the other file tell you where audio and indexes start.

In other cases you will get rxx files. This is a rar archive that must be extracted to revile the rip.

Thanks for the quick replies!

To further clarify, is there any file type that is better to use for Ps1 emulators, or will they all work just as good?

it does not really matter anymore. It did at one time.