Batsman (Batsmen for plural) are a postion in Cricket,this postion is given to player when their team is batting,the people who strike the ball and take runs for the batting team are called Batsmen,two types of Batsman can be on strike,however the one which is facing will be said "on striker" and one that is on the other side is called "non striker" and also "Runner",Its not important that only main Batsman can bat,even Bowlers have to bat if they're number comes and some even to bat good.
They're are different types of batting orders in cricket,one is opener who are the ones who open the match by coming first,the normal order of batsman is 1 down- 3 down and also sometimes 4 or even more consedering what order captain sends them,all-rounders mainly come at around 3-7 down,but they can come earlier regarding when the captain wants them to come,tailenders are the Bowlers who are out to bat they mainly come when most of the team are out and might even come at any order once again consedering what the Captain wants,sometimes bowlers are sent out early to bat in test when there is wet pitch,this is because they don't want their main batsman get out early so they send them late so when the pitch dries they can come and score their runs.