拍卖有好几种，您问哪一类？
Most common types are are:
1. Foreclosure auction, when the house is offered to public. If no other bidder comes, bank will take it.
2. REO auction, when bank has the house, and is trying to sell it at auction.
3. Auction by private parties, including even homeowners, builders,
4. Tax auction, including county and IRS
5. HUD auction, sells FHA foreclosed houses
6. Perhaps even VA houses could be up for auction, not sure though.

Hope this helps
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