Extortion is the practice of obtaining benefit through coercion. In most jurisdictions it is likely to constitute a criminal offence; the bulk of this article deals with such cases. Robbery is the simplest and most common form of extortion, although making unfounded threats in order to obtain an unfair business advantage is also a form of extortion.

Robbery is the crime of taking or attempting to take anything of value by force, threat of force, or by use of fear. According to common law, robbery is defined as taking the property of another, with the intent to permanently deprive the person of that property, by means of force or fear; that is, it is a larceny or theft accomplished by an assault. Precise definitions of the offence may vary between jurisdictions. Robbery is differentiated from other forms of theft by its inherently violent nature ; whereas many lesser forms of theft are punished as misdemeanors, robbery is always a felony in jurisdictions that distinguish between the two. Under English law, most forms of theft are triable either way, whereas robbery is triable only on indictment. The word "rob" came via French from Late Latin words of Germanic origin, from Common Germanic raub "theft".