At any one time, there are two batsmen in the playing area. One takes station at the striker's end to defend the wicket as above and to score runs if possible. His partner, the non-striker, is at the end where the bowler is operating.
Batsmen come in to bat in a batting order, decided by the team captain. The first two batsmen – the "openers" – usually face the most hostile bowling, from fresh fast bowlers with a new ball. The top batting positions are usually given to the most competent batsmen in the team, and the non-batsmen typically bat last. The pre-announced batting order is not mandatory and when a wicket falls any player who has not yet batted may be sent in next.
If a batsman "retires" (usually due to injury) and cannot return, he is actually "not out" and his retirement does not count as a dismissal, though in effect he has been dismissed because his innings is over. Substitute batsmen are not allowed.
A skilled batsman can use a wide array of “shots” or “strokes” in both defensive and attacking mode. The idea is to hit the ball to best effect with the flat surface of the bat’s blade. If the ball touches the side of the bat it is called an “edge”.