Enterprise Server for .NET regions can run in self-hosted or WAS-hosted modes. User applications run within Application Domain threads in a process named SEESEP.EXE for self-hosted mode, or the W3WP.EXE worker process in WAS-hosted mode.
When you debug an application executing within a specified region, a special debug SEESEP.EXE process is created when you start debugging from the Visual Studio IDE.
This SEP registers itself to a specific region, and does not run in a region-agnostic mode as normal SEPs do. The SEP processes only those requests that match the criteria specified in the debug properties of the project.
In whichever mode the region is started, with or without debug support, the applications are monitored in a similar way providing support for CICS timeouts, for example.