The word "'billion", and its matching words in other languages, can mean one of two different numbers.
|At the end of the 17th century, a change was made in the way of writing large numbers. Before the change, they were written into groups of six digits. After that until today, we use groups of three digits, separated by a comma or a space. After the change, some Italian and French scientists began using the word "billion" to mean 109 (one thousand million). They also changed the meaning of trillion and other large number words. The starting point is one thousand instead of one million. This is known in French as the échelle courte ("short scale"). It is used in the US, and because of the US's financial importance, it is used in other English speaking countries too, even changing the dictionary definition. Another word for this number is milliard.|
|The original meaning, started in the 15th century, was "a million of a million" (1,000,0002 which led to the name billion), or 1012. This system, known in French as the échelle longue ("long scale"), is used in most countries where English is not the common language.|