What is the meaning of Billion?

a thousand million (logic: 1,000 × 1,000): 1 followed by nine zeros, 10; a milliard

A million million (logic: 1,000,000): a 1 followed by twelve zeros; 10

An unspecified very large number.

10

trillion (10)

billion (10)

billion, a million-million, 10

Source: wiktionary.org