A fixture is personal property that, by reason of attachment or affixation, has become a part of real property. The most obvious type of fixture is a building. It would also include such elements as plumbing, wiring, fences, septic systems, cabinetry, dams, and so forth.
Once personal property becomes a fixture, it is treated for all intents and purposes as part of that real property. For example, an agreement to sell or mortgage real property includes all the fixtures on that property and cannot be removed by the seller prior to the completion of the sale or the payment of the mortgage.
See also Edit
Trade fixture - one exception to the rule.