Assembly: mscorlib (in mscorlib.dll)
Application domains, which are represented by AppDomain objects, help provide isolation, unloading, and security boundaries for executing managed code.
Multiple application domains can run in a single process, but there is not a one-to-one correlation between application domains and threads. Several threads can belong to a single application domain. Note, however, that although a given thread is not confined to a single application domain, it can run in only one application domain at a time.
The AppDomain class cannot be inherited.