Long and short scales

The long and short scales are two of several different large-number naming systems used throughout the world for integer powers of ten:

Long scale: Every new term greater than million is one million times larger than the previous term. Thus, billion means a million millions (10^12), trillion means a million billions (10^18), and so on.

Short scale: Every new term greater than million is one thousand times larger than the previous term. Thus, billion means a thousand millions (10^9), trillion means a thousand billions (10^12), and so on.

See more at http://en.wikipedia.org/wiki/Long_and_short_scales