the imperium is a vast empire of different chapters ranging from righteus space nazis to crimson red killers.
Space Wolves are a fierce and mean, in your face, close combat Space Marine army. They have special units and rules meant to get the most out of this approach. More than other 'close combat' Chapters, Space Wolves will fail to make any sort of gun line effective for them.
The Space Wolves are a savage and fiercely loyal Chapter of Space Marines – traits inextricably linked to the ferocity of their home world of Fenris. They are taught to fight from a young age, for war is not just their peoples' way of life, but their only means of survival.