You are either buying the property itself or the right to collect debt:
Most auctions require you to register in advance and may ask for a deposit (e.g., 10%–15% of the property value). how to buy tax sale properties
Even after you "win," the original owner often has a legal right of redemption . This is a window (months to years) where they can pay back the taxes plus interest to get their house back. If they pay, you get your money back plus interest. You are either buying the property itself or
You buy a "tax lien certificate." You don't own the house yet; you own the debt. You earn interest on that debt, and if the owner never pays you back, you can eventually foreclose to take the property. 2. The Step-by-Step Process If they pay, you get your money back plus interest