Contingent vs. pending: What’s the difference?

Q: Every time we look for a house (condo, townhouse or single-family home) and find one we like, by the time we go to make an offer, it's always been either contingent or pending. Why? And also, what does pending mean? --Eric B., Las Vegas

A: Eric, it sounds like what's frustrating you is really two separate things: (1) not understanding these classifications and (2) the fact that so many of the homes you like appear to be inactive listings for some reason. So, let's deal with both these issues, in turn.