In short, a property lien means the homeowner has an outstanding debt on a house or another type of property. By placing a lien on the property, the creditor ensures that the owner can't sell the property without satisfying the debt first. They can even force the sale of the property, in some cases. This is why it's important to check liens on a property—imagine putting an offer on a dream home, only to find out that you won't be able to possess the title until the seller clears their debt.