What is a Gangster, you ask? Let me tell you, A gangster is a criminal who is a member of a gang. Some gangs are considered to be part of organized crime. Gangsters are also called mobsters, a term derived from mob and the suffix -ster.Gangs provide a level of organization and resources that support much larger and more complex criminal transactions than an individual criminal could achieve. Gangsters have been active for many years in countries ar