What is the difference between Web.config and Machine.config?

1. The settings configure in the web.config file are appliy to a particular web application
only whereas the settings of machine.config file are applied to the every asp.net application with in a server.

2. Web.config will be for that particular application while the machine.config use for the whole machine.

3. Every ASP.NET application has a web.config file. The settings specified in this will imply only to that application. Whereas you’re System has a machine.config file in Microsoft.NET\Framework\v1.1.4322\CONFIG Folder
which contains specifications and settings at a system level.

4. Web.config file override the settings from the machine.config file. machine.config file settings are applied to all the webapplications residing on the server while web.config settings are application specific.

5. machine.config is created when you install ASP.NET in your machine
Web.config is created when you create an application.