Attack in badminton is the play with the intention to gain points for the victory of a match. Attack is worked out in various ways.
Because the aim of a match is to win it, and this is done by reaching the amount of points to win, and these points are gained by hitting unreturnable, in fact, playing a badminton match is always attacking.

Attacking can be realized in several ways, depending on the playing circumstances, like the own possibilities and wishes, the qualities of the oponent, etcetera.
-Constantly as hard and quickly playing as possible, which leads to difficult shots for the opponent or opponents.
-Involving indirect tactics, like tiring up the opponent, or often changing tempo.
-Involving the strategy to give the opponent no change to play back the shuttle in a difficult way, so self being able to wait for good chances.
-Constantly only playing with the intention to return every shot, so making profit of the opponent's faults.
Combinations are possible.

Often the last two possibilities of attacking are called defending. The intention though is to win and therefor gain points. Thus, these are more indirect attacks in fact.
The intention is always to win the match. The way of attacking in this array is just from very direct to very indirect.