What is Web.Config File?
It is an optional XML File which stores configuration details for a specific
asp.net web application.
What is Machine.config File?
The Machine.Config file, which specifies the settings that are global to a particular machine. This file is located at the following path:
\WINNT\Microsoft.NET\Framework\[Framework Version]\CONFIG\machine.config
As web.config file is used to configure one asp .net web application, same way Machine.config file is used to configure the application according to a particular machine. That is, configuration done in machine.config file is affected on any application that runs on a particular machine. Usually, this file is not altered and only web.config is used which configuring applications.
You can override settings in the Machine.Config file for all the applications in a particular Web site by placing a Web.Config file in the root directory of the Web site as follows:
\InetPub\wwwroot\Web.Config
Macine Config VS WebConfiguration
Difference between Machine.Config and Web.Config
Machine.Config:
i) This is automatically installed when you install Visual Studio. Net.
ii) This is also called machine level configuration file.
iii)Only one machine.config file exists on a server.
iv) This file is at the highest level in the configuration hierarchy.
Web.Config:
i) This is automatically created when you create an ASP.Net web application project.
ii) This is also called application level configuration file.
iii)This file inherits setting from the machine.config