The Goth Subculture is an alternative lifestyle/musical subculture that formed in the early 1980's due to the rise in popularity of Gothic Rock, a gloomy form of Rock music which began in the late 1970's. A member of the Goth Subculture is referred to as a Goth. A Goth seeks to explore the darker aspects of life. These darker aspects include but are not limited to death, depression, suicide, kinky sex, BDSM, the occult and the supernatural. Being dark is a nebulous concept in the Goth Subculture. Due to the fact that the Goth Subculture does not specifically define what it means to be Goth, it is up to each Goth to to create their own dark style. Therefore, there are different types of Goths. They can be generalized into specific types as shown on the website below.
References: Goth Stereo Types: http://www.blackwaterfall.com/gothstereo/about.php