A baron is a member of the lowest rank of British peerage, ranking below a viscount. A female of that rank is a baroness. A baron is said to hold a barony (plural baronies).
Initially, barons were men who held land directly from the monarch. A barony was created in one of two ways: by a writ of summons directing someone to Parliament, or by letters patent. The writ of summons was used in medieval times, but creation by letters patent is currently the norm. Baronies are thus no longer directly related to land ownership.
In Scotland, the word "baron" refers to the holder of a feudal barony, which is related to land ownership. The Scottish equivalent to the English barony is the "Lordship of Parliament." Generally, the more modern baronies pass only to heirs male. However, Scottish Lordships of Parliament and ancient English baronies can be inheirited by a daugter provided she has no brothers.
The word baron is from an Old French word baro for 'man', that is 'vassal'.
In the late twentieth century non-hereditary life peers were introduced in Britain. These have all been barons, though in principle there is no reason why a life peerage of a higher rank should not be created. Normally Baron X is called Lord X and his wife is called Lady X. In the case of women given life peerages of their own, however, the convention is to style them as Baroness X rather than Lady X. The husband of a Baroness in her own right does not recive a style. Children of Barons and Baronesses in their own right, whether the barony is hereditary or for life, are styled The Honourable [Forename] [Surname]. After the death of the father or mother, the child may continue to use the style Honourable.
Baron is the name of several communes in France: