In law, the word means real relevant as distinct from the person. Thus, the law widely distinguishes between "real" property "personal" property. The conceptual difference between the immovable property, which would transfer title to the land side, and movable property, would the person who retains title. Senior use of the phrase "real estate" which had been preserved in historical records was in 1666.
The use of the word "real" to refer to the ground also reflects a preference ancient lands, including ownership. This in turn reflects the values of a feudal regime in the Middle Ages, which is ultimately the root cause of public law.
Real estate is a legal term covering the ground along with anything permanently affixed to the ground, such as buildings, property and this is precisely fixed, or fixed in place. Real estate and is often considered synonymous with real, contrary to personal property, except in some cases, the words "real estate" refers to the land and furniture together, as distinguished from "real property" in reference to the rights of land ownership itself.