Definition of 'British Pound Sterling GBP'

GBP is the three-letter currency code representing
the British Pound which is commonly known as the pound, pound sterling, or just sterling.

The Pound is the third-largest reserve currency, after the US dollar and the euro.
Sterling is also the fourth-most-traded currency in the Forex market after (1) the US dollar, (2) the euro, (3) the Japanese yen.

When the pound is traded against the US Dollar (GBP/USD) in the foreign exchange market then it is referred to as Cable.
It derives its name from the Transatlantic Cable telegraphically linking the UK with the USA,
enabling messages with currency prices to be transmitted between the London and New York Exchanges.

In Britain you will often hear the pound referred to a quid.
Quid is never pluralized so you would say "a quid" for 1 pound as you would say "50 quid" for 50 pounds.