05024ba1_nfig_Inheritance_and_Overrides__Configuration_level
[File name] Web.config [File description] The Web.config file for the server is stored in the same directory as the Machine.config file and contains default values for most of the system.web configuration sections. At run time, this file is merged second from the top in the configuration hierarchy. [Configuration level] 
Root Web
S e r v e r
I I S
R o o t W e b
W e b s i t e
A S P . N E T a p p l i c a t i o n r o o t d i r e c t o r y
A S P . N E T a p p l i c a t i o n s u b d i r e c t o r y
Jon Galloway - 10 Things ASP.NET Developers Should Know About Web.config Inheritance and Overrides
Configuration level