It's basically a rendering algorithm involving color bleed that radiates from one object to strike another, much like the way light bounces while absorbing color in the real world. 

Because of it's rendering speed and quality, it has become the obvious choice for photo-realistic rendering which comes with my 3D software of choice SoftImage XSI. 

Among other things, I will showcase some of my best work. I will also show you how to achieve photo-realistic rendering in a couple of easy steps by using the final-gathering algorithm in the tutorial section.  Enjoy...