What is the meaning of Billion?

Either of two large amounts:

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

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

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

   An unspecified very large number.

   10

   trillion (10)

   billion (10)

   billion, a million-million, 10

   Source: wiktionary.org