Second Life (SL) is a virtual world developed by Linden Lab. It's almost like Maxis' The Sims, but with online architecture. Although SL can be categorized as an MMORPG, but it's obviously quite different from the likes of WoW, Lineage, etc. There's no leveling inside the SL world. What's most important in the second life concept is to give the users (residents) a second chance to build their lives. Residents in SL has their own avatar. They can create their own things (or just buy them with the SL world's currency). SL used a 3D dimensional modeling tools that was build around simple geometric shapes. If you aware of software like 3dsMax or MAYA, you could also import them to the SL world.
Second Life has its own currency, which is called Linden Dollar (L$). L$ can be used as a mean of tradings inside the SL world. There's also a currency exchange available for L$ as in the First Life (Real World), which is 250L$ for 1USD.
Nowadays, there are branded companies such as IBM, CISCO, Adidas, Sony, Vodafone, etc that mostly share their new concepts in SL world.
To sum everything up, SL is not just a game, but it's a virtual world that could connect to the real world, and maybe in the future, it could change the way of living. Imagine, a CEO that needs to be in two meetings, by using SL, he could just send his avatar to substitute his body.
