Billion is a name for a large number. There are two different meanings for the term:

• 1,000,000,000 (10⁹, one thousand million) is the short scale definition. It is used in both British and American English. The short scale has been used in the United Kingdom since 1974. Its prefix is “giga-“.
• 1,000,000,000,000 (10¹², one million million) is the long scale definition. It was formerly used in the United Kingdom. It is currently in some other countries. When “billion” has this meaning, the word “milliard” can be used for “thousand million”.

Some examples of billion meaning thousand million:

• Over 1.3 billion people live in India.
• The total land area of Russia is 1.71 billion hectares.
• Billionaires are very rich people. Their wealth is in the billions of dollars, euros or pounds sterling.
• The Age of the Earth is about 4.5 billion years.
• One billion seconds is about 31.5 years.
• The distance to the planet Saturn from the Sun varies from 1.4 billion km to 1.5 billion km.

Billion may also refer to:

• Billions (TV series), a Showtime series
• Billions (movie), a 1920 silent comedy
• Billion (company), a Taiwanese modem manufacturer
• Jack Billion (born 1939), 2006 Democratic Party candidate for governor of South Dakota
• Mr. Billion, a 1977 movie by Jonathan Kaplan
• "Billions" (song), a song on Russell Dickerson's album Yours