What is managed code and managed data?

Managed code is code that is written to target the services of the Common Language Runtime. In order to target these services, the code must give a minimum level of information (metadata) to the runtime. All C#, Visual Basic .NET, and JScript .NET code is managed by default. Visual Studio .NET C++ code is not managed by default, but the compiler can make managed code  by specifying a command-line switch (/CLR).

Closely related to managed code is managed data--data that is allocated and de- allocated by the Common Language Runtime's garbage collector. C#, Visual Basic, and JScript .NET data is managed by default. C# data can, though, be marked as unmanaged through the use of special keywords. Visual Studio .NET C++ data is unmanaged by default (even when using the /CLR switch), but when using Managed Extensions for C++, a class can be marked as managed using the __gc keyword.