This is what we found on Wikipedia regarding the KFC Twenty 20 Big Bash:

Twenty20 (abbreviated T20) is a shortened format of cricket. At the professional level, it was introduced by the England and Wales Cricket Board (ECB) in 2003 for the inter-county competition. In a Twenty20 game, the two teams have a single innings each, which is restricted to a maximum of twenty overs (which is equivalent to 120 legal deliveries per team). Together with first-class and List A cricket, Twenty20 is one of the three forms of cricket recognised by the International Cricket Council (ICC) as being played at the highest level, both internationally and domestically.

A typical Twenty20 match lasts just over 3 hours, with each innings lasting around 90 minutes and an official 10-minute break between the innings. This is much shorter than previous forms of the game, and is closer to the timespan of other popular team sports. It was introduced to create a fast-paced game that would be attractive to spectators at the ground and viewers on television.

The game has succeeded in spreading around the cricket world. On most international tours there is at least one Twenty20 match and all Test-playing nations have a domestic cup competition.