Twenty Cricket is the shortest (duration wise) version of cricket, with matches usually lasting around three hours.

Twenty cricket is a modified version of traditional cricket. Twenty cricket consists of only one inning per team and a maximum of 20 batsmen per team, thus resulting in a much shorter game lasting around three hours.

The goal of twenty cricket is to score more points that the opposing team at the end of regulation. If the score is tied at the end of regulation, a sudden death bowl-out is conducted to determine the winner.

Standard laws of cricket apply to this form with some exceptions being that both teams have a single inning and bat for a maximum of twenty overs. Each bowler may bowl a maximum of only one-fifth of the total overs per innings (generally four, for a full, uninterrupted game). Umpires may award five-run penalty runs at their discretion if they believe either team is wasting time. If the fielding team does not start to bowl their 20th over within 75 minutes, the batting side is credited an extra six runs for every whole over bowled after the 75 minute mark; the umpire may add more time to this, if he considers the batting team is wasting time. If the match ends with the scores tied and there must be a winner, the tie is broken with a bowl-out (similar to a penalty shoot-out in football), with five bowlers from each side delivering 1 ball each at an unguarded wicket. If the number of wickets is equal after the first five balls per side, the bowling continues and is decided by sudden death. Should a bowler deliver a no ball by overstepping the popping crease, it costs 1 run and his next delivery is designated a free-hit, from which the batsman can only be dismissed through a run out, for hitting the ball twice, obstructing the field or handling the ball, as is the case for the original "no ball."

Twenty cricket originated sometime in 2003 as a way to shorten the length of the game, create a livelier form of the game, and be a more attractive form to spectators. The first game of twenty cricket was played on July 15, 2004 between Middlesex and Surrey. The first international game was not played until Australia defeated New Zealand on February 17, 2005. Since that match, 12 countries have participated in the format. The ICC has set a world tournament of twenty to occur every two years. The inaugural tournament was played in 2007 and won by India.

Ball
Bat
Stumps
Wicket

Since twenty cricket is essentially a shorter version of traditional cricket, training for the sport is similar with an emphasis on knowing the differences in the laws.

Bails - two small sticks placed on the three stumps that comprise the wicket and determine when the wicket is broken

Innings - a fixed length of time lasting until ten out eleven batsmen are out

Over - a set of six consecutive balls bowled in succession

Pitch - the central strip of the cricket field between the wickets that is 22 yards long and 10 feet wide

Stumps - three vertical posts which support two bails

Wicket - one of the two sets of three stumps and two bails at either end of the pitch

http://en.wikipedia.org/wiki/Twenty20