Process undergone before ApplicationStart method - .NET MVC Website

When I click on the "Run" option in Visual Studio of my Web application, it builds all the projects, and my browser is openned.

It takes a minimum of 3 minutes from my browser window openned and the breakpoint hits in my application start method in my global.asax file.

What are the process that is undergone before the ApplicationStart method ?

Can some one explain as am new to .NET.

Thanks in advance.