An application domain is a mechanism (similar to a process in an operating system) used within the Common Language Infrastructure (CLI) to isolate executed software applications from one another so that they do not affect each other. Each application domain has its own virtual address space which scopes the resources for the application domain using that address space.
Creating multiple application domains in the same process is not possible in .NET Core and .NET 5+.[1]
- ^ ".NET Framework technologies unavailable on .NET Core and .NET 5+". Microsoft Docs. Archived from the original on 2019-04-20. Retrieved 2021-02-02.