In law, the word real means relating to a thing (from Latin res, matter or thing), as distinguished from a person. Thus the law broadly distinguishes between [real property] (land and anything affixed to it) and [personal property] (everything else, e.g., clothing, furniture, money). The conceptual difference was between immovable property, which would transfer title along with the land, and movable property, which a person would retain title to. (The word is not derived from the notion of land having historically been "royal" property. The word royal — and its Castilian cognate real — come from the unrelated Latin word rex, meaning king.)

With the development of private property ownership, real estate has become a major area of business. Purchasing real estate requires a significant investment, and each parcel of land has unique characteristics, so the real estate industry has evolved into several distinct fields. Specialists are often called on to valuate real estate and facilitate transactions. Within each field, a business may specialize in a particular type of real estate, such as residential, commercial, or industrial property. In addition, almost all construction business effectively has a connection to real estate."Internet Real Estate" is a term coined by the internet investment community relating to the parallel that exists between high quality internet domain names and real-world, prime real estate.