Can someone define these terms to a student researching foreclosures?

Ryan T asked:


I compiled a list of foreclosures off realtytrac.com and I am doing a demographic study of the affected zip code. The web site differentiates between the following terms:

Pre-foreclosure; Auction; Bank-owned; FSBO; Resale

Any knowledge at what determines the housing status would be greatly appreciated, it doesnt have to be too detailed, I just want to be able to filter what I need.