"Concession" is an abstract term for the process of conceding a point to someone.  It is also used to cover dismissing or rebutting in argument.  We use certain concessive markers (although, however) to indicate:

a) which authors/views are being dismissed or rebutted (because you disagree with them) &

b) which are being promoted or defended (because you agree with them).

Using these markers to acknowledging alternative points of view shows awareness of, and respect for, the value or stance of those views - even if you disagree with them. The whole point is that, although you will then go on to challenge or dismiss those views, your use of concession lends balance to your criticism [notice how this sentence does the same thing!]. And at a social level there is also the question of  face. Wouldn’t you want your own work similarly respected by other people who may not agree with you !?

Let’s transform a statement which is currently a crude assertion:

"Students refuse to accept direct rule from China"

and make it into a more delicate proposition, following steps 1-6 in the Language delicacy program, as follows:

So's (1993) study of 300 6th form students in Hong Kong indicates that many students may be prepared to accept direct rule from Beijing if their separate Hong Kong identity is respected.

Now let's challenge this assertion by So. 
We could replace `indicates’ with "wrongly claims that". But this, too, would lack delicacy.
A more elegant solution is to introduce someone’s point first, and then to challenge it. This is where we use the argumentative strategy of concession.
E.g.:

"So's (1993) study of 300 6th form students in Hong Kong indicates that many students may be prepared to accept direct rule from Beijing if their separate Hong Kong identity is respected"

à [But I disagree that this is the majority opinion ! So I write….] à

"Although So's (1993) study of 300 6th form students in Hong Kong seems to indicate that many students may be prepared to accept direct rule from Beijing if their separate Hong Kong identity is respected, more recent studies show Hong Kong students expressing a combination of a strong sense of Chinese identity and general indifference to the political implications of 1997" (Chan, 1996; Wong, 1997).

* If you're familar with this concept and how it is used, return to the language delicacy sequence [7. Concession], using our "nurses" example