is a polite expression that is used for asking people to do something. It is most often translated as ‘please do (A)’.
Please wash your hands.
Please look at this.
is actually classified as 尊敬語（そんけいご）, a type of polite speech that is used to refer to the actions of other people. くださる itself is the base form of this verb. While ください
is exclusively used for making requests. くださる is the polite (sonkeigo) equivalent of くれる
In friendly conversation, ください
can be omitted from this expression, and the て
form itself can be used as a very casual way of saying ‘please do (A)’.
Hey, can you turn off the TV? (ちょっと is often used simply to get the attention of the listener)
Because I made cookies, you can eat them.