global.asax

ASP.NET application file Reference

An .asax file is an application file for ASP.NET. The known file is global.asax, which handles application events such as start, end, and errors. The code runs on the web server, and the server refuses direct requests for the file. The logic itself frequently lives in a code-behind file. One web application has at most one global.asax.

A file extension is only a part of the file name. It does not give a guarantee about the format or the content of a file. But on Windows, the extension selects the program that opens the file.