Tracing is a way for you to monitor the execution of your application while it is running. You can add tracing and debugging instrumentation to your .NET Framework application when you develop it, and you can use that instrumentation both while you are developing the application and after you have deployed it. You can use the System.Diagnostics..::.Trace, System.Diagnostics..::.Debug, and System.Diagnostics..::.TraceSource classes to record information about errors and application execution in logs, text files, or other devices for later analysis.

Instrumenting your application by placing trace statements at strategic locations in your code is especially useful for distributed applications. By using trace statements you can instrument an application not only to display information when things go wrong, but also to monitor how well the application is performing.

The TraceSource class provides enhanced tracing features and can be used in place of the static methods of the older Trace and Debug tracing classes. The familiar Trace and Debug classes are still widely used, but the TraceSource class is recommended for new tracing commands, such as TraceEvent and TraceData.

The Trace and Debug classes are identical, except that procedures and functions of the Trace class are compiled by default into release builds, but those of the Debug class are not.

The following topics provide additional information on using instrumentation in your applications.