Out: The raised finger from the umpire is the signal all batsmen dread. As soon as that finger goes up, the batter has to go.
Four: When a ball is hit to the boundary the umpire signals a four. The boundary four is signalled by waving an arm from side to side, finishing with the arm across the chest. Each umpire has his own way of signalling a four.
Six: When the ball is hit clean over the boundary the umpire will signal a six by raising both hands above his head. Some umpires raise three fingers on each hand to further signal the six, or perhaps all five on one hand and one on the other.
Bye: If a delivery passes the batsman and fielder it is known as a bye. It is a legal delivery passing the stumps with the ball touching neither the bat nor the batsman's body. The umpire's signal is one arm stretched high above the body.
Leg bye: Called when a ball hits any part of the batsman's body (except the hand holding the bat) and not the bat. It is signalled with a hand touching the umpire's raised knee.
Wide: A delivery too wide for a batsman to play a shot. It is signalled with both arms outstretched. The umpire will judge a delivery to be wide if it is out of the reach of the batsman and he is unable to play a correct cricket shot.
Dead ball: This indicates the previous bowl is cancelled and is signalled by the crossing of the wrists below the knee. If the ball comes off a batsman's pad without him attempting a shot then a dead ball is called to negate any score.
No ball: This is signalled by an arm raised at shoulder height. The most common no ball is the foot-fault; a bowler bowling too many intimidating deliveries in an over, or bowling full-toss above the batsman's waist can also be no balled.
New ball: In Test cricket, the fielding side may request a new ball after it has been in use for 80 overs. The batsmen are informed and the umpire indicates the new ball to the scorers by raising it in the air.
Cancel call: At times even umpires can get their decisions wrong. If they wish to alter a decision, they can cancel the call by touching each shoulder with the opposite hand. It doesn't happen very often and would rarely be seen in any match.
Last hour: In Tests there is a minimum number of overs to be bowled in a day and at least 15 must be bowled in the last hour of the final day. In county cricket, when 96 overs have to be bowled, 80 overs must be played before the last hour can start.
One short: A batsman failing to make his ground when turning between runs is guilty of one short. This would be called when a batsman is running two or more, but fails to make his ground and puts his bat in short at one of the turns.
TV replays: Run-outs, stumpings, doubtful catches and boundary issues can all be passed on for a TV replay. The third umpire is called upon to look at TV replays by a field umpire. They cannot be called upon for lbw decisions.
Penalty runs: These are treated like byes and leg byes as they are added to the extras. They could come into play for things like illegal fielding, time-wasting and the fielders damaging the pitch; warnings would be given first.