Second Life is a 3-D virtual world entirely built, inhabited and owned by its residents. Depending on who’s stats you belive, there are something like The SL Wikipedia entry reads, “Developed by Linden Labs, a downloadable client program enables its users, called “Residents”, to interact with each other through motional avatars, providing an advanced level of a social network service combined with general aspects of a metaverse. Residents can explore, meet other Residents, socialize, participate in individual and group activities, create and trade items (virtual property) and services from one another.”
The SL website is the place where users download a copy of the SL application. The SL client operates on the users PC or Macintosh and connects to a Grid (need refernce) of SL servers via the internet.