What is Marshalling?

Marshalling is medium or gateway to communicate with an unmanaged code from managed code in better way and vice versa, by using pinvoke, and ensures that data is returned back in a safe manner.

It is one of the core services offered by CLR (Common Language Runtime).

Because most of types in unmanaged environment do not have counterparts in managed environment, so we have to create conversion routine that convert manage types into unmanaged types and vice versa.

We call .Net code “Managed code” because it is controlled by CLR. Other code that is not managed by the CLR is called as unmanaged code.