A lien is a legal claim against a property that secures a debt, giving the lien holder the right to be paid from the proceeds when the property sells, before the owner sees any money. Liens include mortgages, unpaid taxes, judgments and contractor bills, and more than one can attach to the same property, generally paid in the order they were recorded.
Why it matters
Every lien against your house gets paid at closing before you do, which can shrink or wipe out your proceeds.
General information, not legal or tax advice.