A property lien is a legal claim against a property that ensures a debt is paid. When a property owner owes money, such as for a mortgage or unpaid taxes, the lender or government can place a lien on the property. This means the owner cannot sell or refinance the property without first settling the debt. Liens can be voluntary, like those from a mortgage, or involuntary, such as tax liens. If the debt remains unpaid, the lienholder may have the right to foreclose on the property, allowing them to recover the owed amount through a sale of the property.