Real estate or immovable property is a legal term (in some jurisdictions) that encompasses land along with anything permanently affixed to the land, such as buildings. Real estate (immovable property) is often considered synonymous with real property (also sometimes called realty), in contrast with personal property (also sometimes called chattel or personalty). However, for technical purposes, some people prefer to distinguish real estate, referring to the land and fixtures themselves, from real property, referring to ownership rights over real estate.
The terms real estate and real property are used primarily in common law, while civil law jurisdictions refer instead to immovable property.
In law, the word real means relating to a thing (from Latin res/rei, 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 related Latin word rex-regis, meaning king.)