"Second Life is a 3-D virtual social networking world entirely built and owned by its residents. Since opening to the public in 2003, it has grown explosively and today is inhabited by a total of 6,240,591 people from around the globe." Second Life allows each user to create his or her own avatar, offering a large degree of freedom in choosing one's appearance. As a result, most Second Life users' avatars differ significantly in looks from their real-life operators (for example, Jason, in Second Life, has green skin), and relatively few users create their Second Life avatars as a near exact representation of their real selves (like Henry Jenkins). As Donald Jones, mentions in his essay "I, Avatar" in Second Life, you have the opportunity to be your perfect self. It allows for people with disabilities to interact in ways that they cannot in real life. You can be someone completely different either--the two common appearances are really attractive people or really weird fantastic people.
Second Life is unlike any other MMO because the goal or function of Second Life is entirely user-determined. As a result, the world of Second Life has been built from the bottom up to cater to almost anything a Second Life user could want, from creating original art and attending lectures to greed and lust. The goal in Second Life, if there is any, is to participate in socialization, commerce, and creativity. Some people and companies use Second Life as a commercial tool. Many large businesses (Reebok, Apple, and Nike, for example) have established headquarters in Second Life that advertise their real life products. People can even make money by selling their intellectual property--houses, vehicles, land. Anyone can build anything they want using simple tools and then sell it. Owning property enables a sense of place and self, a very real feeling. Jones discusses this by describing it as the "rip, mix, and burn" reality. Second Life takes reality and bends it, alters it, so that it is recognizable as our own life while keeping it a fantasy at the same time. In this way, it can be categorized a virtual reality.
Donal Jones: "I, Avatar: Constructions of Self and Place in Second Life, and the Techological Imagination"
http://www.secondlife.com/ Second Life Homepage
Donal Jones: "I, Avatar: Constructions of Self and Place in Second Life, and the Techological Imagination" http://gnovis.georgetown.edu/articles/FA05-01-secondlife.pdf