Billion
From ACT Wiki
1.
One thousand million (1,000,000,000 or 109).
For example
EUR 100 billion = EUR 100,000,000,000.
Often abbreviated to 'bn' or 'Bn'. For example EUR 100bn.
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.