Billion
From ACT Wiki
1.
One thousand million (1,000,000,000 or 109).
For example
EUR 456 billion = EUR 456,000,000,000.
Often abbreviated to 'bn' or 'Bn'. For example EUR 456bn.
2.
Historically in the UK and some other countries, 'billion' used to refer mathematically to 1,000,000,000,000 (or 1012).
This historical usage never became well-established in finance, and is now - for practical purposes - defunct.