The Killer—With notable exceptions, the killer in the slasher film is usually male. His identity is often, but not always, unknown and/or concealed either by a mask or by creative lighting and camera work. He is often mute and seemingly unstoppable, able to withstand stabbings, falls and shootings by his victims. His background sometimes includes a childhood trauma that explains his choice of victim, weapon and location (the killer can be made out to be pitiable or understood). Slasher villains tend to prefer hand held weapons such as knives, axes, hatchetes, and chainsaws as opposed to bombs or guns. As the sub-genre developed, some argue that the real star of a slasher is the killer, not the victims or Final Girl. Throughout most of the franchises, the killer is constant. Freddy Krueger, Jason Voorhees and Michael Myers are notable examples of this phenomenon.
The Victims—The victims tend to be young, attractive, high school or college-aged adolescents. Much has been made about the choice of victims. Some theorists claim that they young people are punished for indulging in vices such as pre-marital sex or illegal drugs. Other theorists claim that is simply a matter of the activities making the victims unaware of their surroundings, making them easy prey for the killer.
Source: (wikipedia.org/wiki/Slasher_film )