Yeah I don't know what mounting is. Krizz said he was going to make a guide but I haven't heard from him.
Here I'll explain:
An ISO or BIN file are essentially disc image files.
An exact copy of a disc put into a file.
However, to be readable, you need something to imitate hardware to run that disc. What mounting software does is it makes a fake dvd-rom/blu ray, whatever drive and "mounts" the disc image file into that fake disc drive and runs it.
From there it would be the exact same as if you put the disc in your optical drive. You can install the game you want, and play it while mounted.
The only downside to that is it takes up significantly more space because you're still installing whatever is on the disc image onto your hard drive, yet running the disc image instead of putting an actual disc in to play every time.