Render settings explanation?

[APrather]

Are there any explanation render setting especially with basic configuration and GI? Such as brief explanation What are  they, and how it is it used. And so on.  So I can have better understand how to use it for future....  Here's one example. I am struggling to understand why Bldr/VCA just won't display 100% glossy material as to Progressive.. Why? I don't even know what Bldr/VCA is, or how its used. 

[Ludvik Koutny]

Hi, you should mostly use Path Tracing and HD cache solutions in progressive mode. Rest of the modes are very experimental and useful only for testing, not actual production. ;)

[APrather]

Thank you for clarification.