In ASP.NET, the Global.asax event Application_End occurs when the application domain is shutting down and the ASP.NET application is ending. Is this description correct or incorrect?

Introduction / Context:
Just as Application_Start marks the beginning of an ASP.NET application domain, Application_End marks its end. This event allows developers to perform final cleanup before the application is unloaded. While it is not guaranteed to run in every scenario, such as abrupt process termination, understanding when Application_End is supposed to fire is important for reasoning about application life cycle and resource management.

Given Data / Assumptions:

• We are working with an ASP.NET application hosted in IIS or a similar environment.
• The Global.asax file may define an Application_End event handler.
• The statement says Application_End occurs when there are no more users and the application is ending.

Concept / Approach:
Application_End is raised when the ASP.NET application domain is being unloaded. This can happen for several reasons: the application pool is recycled, the web server is shutting down, configuration files such as web.config change, or the application is explicitly stopped. While the event is not literally tied to counting users, it is conceptually associated with the application finishing its lifetime. During Application_End, you can attempt to release resources, close log files, or perform final logging, although long running work is discouraged.

Step-by-Step Solution:
Step 1: The application runs and serves user requests for some period while its application domain is active. Step 2: Eventually, a trigger causes the application domain to shut down, such as an IIS recycle, server stop, configuration change, or idle timeout. Step 3: As part of the shutdown sequence, the ASP.NET runtime raises the Application_End event in Global.asax. Step 4: Any code in Application_End executes, allowing the application to log shutdown details or release managed resources that need explicit cleanup. Step 5: After Application_End completes, the application domain is unloaded and no more requests are processed until a new application start occurs.

Verification / Alternative check:
You can verify Application_End by placing logging statements in the handler and then recycling the application pool or touching web.config. After the recycle, you should see a corresponding log entry. Note that if the worker process is killed abruptly, Application_End may not fire, which is why it is not a suitable place for critical guaranteed cleanup. Documentation on ASP.NET life cycle events confirms that Application_End is associated with application domain shutdown, not with individual requests.

Why Other Options Are Wrong:
Option B is wrong because Application_End is not tied to postbacks and does not run on every request. Option C is incorrect because operating system desktop events such as locking the screen do not directly control ASP.NET application end events. Option D is clearly wrong because Application_End is part of ASP.NET, not SQL Server.

Common Pitfalls:
Developers sometimes assume Application_End will always fire and try to perform critical operations there, such as writing final data to a database; this can be unreliable if the process terminates unexpectedly. Another pitfall is doing heavy work or blocking operations inside Application_End, which can delay process shutdown. It is better to design applications so that important data is flushed earlier and Application_End is used mainly for lightweight logging or resource release where possible.

Final Answer:
The description is essentially correct, because Application_End fires when the ASP.NET application domain is shutting down and the application is ending, typically due to process shutdown or recycle events.