B meaning in Measurement Unit ?

What is Billion mean?

A billion is a number with two distinct definitions:

1,000,000,000, i.e. one thousand million, or 109 (ten to the ninth power), as defined on the short scale. This is now the meaning in all English dialects.1,000,000,000,000, i.e. one million million, or 1012 (ten to the twelfth power), as defined on the long scale. This is one thousand times larger than the short scale billion, and this number is now normally referred to as one trillion. This is the historical meaning in English (with the exception of the United States), and was still in official use in British English until some time after World War II. It is still in use in many non-English-speaking countries where billion and trillion 1018 (ten to the eighteenth power) or equivalent words maintain their long scale definitions.

American English adopted the short scale definition from the French (it enjoyed usage in France at the time, alongside the long-scale definition). The United Kingdom used the long scale billion until 1974, when the government officially switched to the short scale, but since the 1950s the short scale had already been increasingly used in technical writing and journalism.

Other countries use the word billion (or words cognate to it) to denote either the long scale or short scale billion. (For details, see Long and short scales § Current usage.)

Milliard, another term for one thousand million, is extremely rare in English, but words similar to it are very common in other European languages. For example, Bulgarian, Catalan, Croatian, Czech, Danish, Dutch, Finnish, French, Georgian, German, Hebrew (Asia), Hungarian, Italian, Kazakh, Kyrgyz, Lithuanian, Norwegian, Persian, Polish, Portuguese, Romanian, Russian, Serbian, Slovak, Slovene, Spanish, Swedish, Tajik, Turkish, Ukrainian and Uzbek — use milliard (or a related word) for the short scale billion, and billion (or a related word) for the long scale billion. Thus for these languages billion is thousand times larger than the modern English billion.

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