What does a Night Auditor do at hotels?

I am applying for a night audit position at the Holiday Inn, and I really wan't this job. Only thing is I don't have any hotel experience and a little unsure of everything the auditor does. Could any please explain some things I should research about this job so I have a better idea at the interview tomorrow. Like what they do, what they should know, etc. This job is very important to me so any advice would be great thanks.