The term masturbation refers to ‘self abuse’, and most commonly associated with male practices. Masturbation has been around ever since known records have established. However masturbation is still a much of a taboo subject in many religious and are also condemned. However through out time it has been known as a natural part of development, and self-exploration of his or her sexuality. It is easy to say that the act of masturbation is normal and not out of the ordinary, but there will always be a social barrier prevent people from talking about it openly.
The below site offers you a in depth reason people masturbate, and the reason for masturbation. It also explains that it is totally natural, and one shouldn't be ashamed of it.
However this site gives a different opinion on masturbation, and the reasons why masturbation's should be outlawed.