Stock Market Terminologoy: Clearance and Settlement

I’ve got a job interview with a securites firm for a position in the back office (as opposed to the actual selling of securities), also know as clearance and settlement. Now, I’ve worked in this area, but it was over ten years ago, and I’m trying to refresh my memory as to what is important to know. Does anyone know specific terms and concepts that might be used in such a position? (I’ve found a website called investorwords.com, and while helpful, it’s not quite as specific as I would like). Any help would be greatly appreciated!