The pound sterling, commonly called the pound, is the official currency of the United Kingdom, its Crown Dependencies (the Isle of Man and the Channel Islands) and the British Overseas Territories. It is subdivided into 100 pence (singular: penny).
Sterling is the fourth most traded currency in the foreign exchange market, after the US dollar, the euro and the Japanese yen. Together with those three currencies it forms the basket of currencies which calculate the value of IMF Special Drawing Rights. Sterling is also the third most held reserve currency in global reserves.
The full, official name, pound sterling, (plural: pounds sterling) is used mainly in formal contexts and also when it is necessary to distinguish the United Kingdom currency from other currencies with the same name. Otherwise the term pound is normally used.
The currency name is sometimes abbreviated to just sterling, particularly in the wholesale financial markets, but not when referring to specific amounts; for example, "Payment is accepted in sterling" but never "These cost five sterling". The abbreviations "ster." or "stg." are sometimes used. The term British pound is commonly used in less formal contexts, although it is not an official name of the currency. A common slang term is quid (singular and plural) which is thought to derive from the Latin phrase "quid pro quo".
There is some uncertainty as to the origin of the term "pound sterling". Some sources say it dates back to Anglo-Saxon times, when coins called sterlings were minted from silver; 240 of these sterlings weighed one pound, and large payments came to be made in "pounds of sterlings". Other references, including the Oxford English Dictionary, say a sterling was a silver penny used in England by the Normans, and date the term to around 1300.
The currency sign is the pound sign (£) which is usually written with a single cross-bar, as on sterling bank notes, though a version with a double cross-bar (₤) is also sometimes seen. The pound sign derives from the black-letter "L", an abbreviation of Librae in Roman £sd units (librae, solidi, denarii) used for pounds, shillings and pence in the British pre-decimal duodecimal currency system. Libra was the basic Roman unit of weight, derived from the Latin word for scales or balance.
Always remember that trading foreign exchange on margin carries a HIGH LEVEL OF RISK, and may not be suitable for all investors. Before deciding to trade foreign exchange you should carefully consider your investment objectives, level of experience, and risk appetite. The possibility exists that you could sustain a loss of some or all of your initial investment and therefore you should not invest money that you cannot afford to lose. You should be aware of all the risks associated with foreign exchange trading, and seek advice from an independent financial advisor if you have any doubts.