ASP.NET Applications
An ASP.NET application is defined as all the files, pages, handlers, modules, and executable code that can be invoked from a virtual directory and its subdirectories on a Web application server. You can use any of the ASP.NET programming models within any application you define, based on either Web Forms or XML Web services. They must coexist in a single virtual directory structure.
See Also
Creating ASP.NET Web Applications | Introduction to ASP.NET | Application State | Global.asax File | Global.asax Syntax