Concession is a literary device used in argumentative writing where one acknowledges an opposing view of the topic being mentioned. It shows that the writer is mature and fair-minded and fully understands the issue from all angles. This type of writing also shows that one is a logical and strategic thinker who can find a common ground between himself and the opponent.
Example-
“I said earlier that the decadence of our language is probably curable. Those who deny this would argue, if they produced an argument at all, that language merely reflects existing social conditions, and that we cannot influence its development by any direct tinkering with words or constructions. So far as the general tone or spirit of language goes, this may be true, but it is not true in detail.”
(“Politics and the English Language” by George Orwell)