Fixture
The law of property draws a distinction between real property, such as land, and personal property. Personal property is typically property that is movable; the owner (or someone else) can transport the personal property from one place to another. Real property cannot be moved because its boundaries are determined by geography itself.
But what about personal property attached to the land? When personal property is attached to the land with the intention that the personal property become part of the real property, such property is called a fixture. Traditionally, movable personal property becomes a fixture (and thus part of the immovable real property) when it is physically fastened to or connected with the real property in some way that ultimately enhance the real property's value. Thus, an air conditioning unit is movable property prior to its installation. The HVAC company can load the unit on a truck and take it anywhere. But when the unit is purchased by the property owner, bolted down outside, and installed with the intent of cooling a building, the unit becomes a fixture.
In the normal real property transfer contract, fixtures are included in the transfer even if they are not itemized. So, the seller of a house would not normally need to itemize how many bricks were used to build the fireplace as part of the sale because the bricks and the resulting fireplace are a fixture that accompanies the sale of the house.