The code which is developed outside the dot net framework application domain but can be executed in .Net domain is known as managed code.this code execute in unmanaged code execution process.
It uses wrapper classes.
There are two types of Wrappers
1.
CCW(Compile Time Callable Wrapper)
Unmanaged source code executes.
2.
RCW(Run Time Callable Wrapper)
Unmanaged compiled code executes.