A lien is a legal notice attached to your property — your house, your car — saying you owe someone money and the property stands behind the debt. You can still live in the home, but you cannot cleanly sell or refinance it until the lien is paid off and officially released. Common kinds: tax liens, contractor (mechanic's) liens, and court judgment liens.
A lien does not take your property. It does something quieter and, in its way, just as powerful: it puts the debt on the record, attached to the property itself. From then on, the property cannot change hands with a clean title until the debt is settled. Anyone who checks the property's title — a buyer, a lender — sees the claim.
How liens happen
Tax liens come from unpaid property or income taxes — the government files its claim on what you own. Mechanic's liens come from unpaid work on the property: a contractor or supplier who was not paid for a roof, a remodel, or materials can file one. In many states, subcontractors and suppliers can file even if you paid your main contractor and they failed to pass the money along — one of homeownership's nastiest surprises. Judgment liens come from losing a court case over a debt.
You refuse to pay the last $6,500 on a roofing job, convinced the work was shoddy. The roofer files a mechanic's lien. Two years later you sell the house. The title search finds the lien, and closing cannot finish until it is settled — the $6,500, plus whatever interest and costs the law allows, comes out of your sale money before you see a dime. The argument you meant to have someday gets held at the closing table instead.
How a lien goes away
The debt gets paid or settled, and then a release — sometimes called a satisfaction — gets filed in the same public records where the lien lives. That second step matters as much as the first: the release is what clears the title. Liens also typically carry deadlines — a contractor, for example, often has a limited window to enforce one in court or it expires — but expiration rules vary a lot by state and type.