Real estate is a legal term that encompasses land along with anything permanently affixed to the land, such as buildings. Real estate 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 recent years, many economists have recognized that the lack of effective real estate laws can be a significant barrier to investment in many developing countries. In most societies, rich or poor, a significant fraction of the total wealth is in the form of land and buildings. In most advanced economies, the main source of capital used by individuals and small companies to purchase and improve land and buildings is mortgages -- bank loans for which the real property itself constitutes collateral. Banks are willing to make such loans at favorable rates in large part because if the borrower does not make payments the lender can foreclose, that is file a court action that lets them take the property and sell it to get their money back. But in many developing countries there is no effective means by which a lender could foreclose, so the mortgage loan industry as such either does not exist at all or is only available to members of privileged social classes.

In spite of the name, real estate has no connection with the concept of reality (in other words, the law does not consider real property more "real" than personal property). It derives instead from the feudal principle that in a monarchy, all land was considered the property of the king. Thus originally the term real estate was equivalent to "royal estate", real originating from the French royale, as it was the French-speaking Normans who introduced feudalism to England and thus to the English language; cognate to Spanish real.

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. Some kinds of real estate businesses include:

Appraisal - Professional valuation services
Brokerages - Assisting buyers and sellers in transactions
Development - Improving land for use by adding or replacing buildings
Property management - Managing a property for its owner(s)
Relocation services - Relocating people or business to different country

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.

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Levels
According to The Economist, "developed economies'" assets at the end of 2002 was

Residential property: $48 trillion
Commercial property: $14 trillion
Equities: $20 trillion
Government bonds: $20 trillion
Corporate bonds: $13 trillion
Total: $115 trillion