Introduction › Microsoft .NET › Terminology › Common Language Runtime

Common Language Runtime

The Common Language Runtime (CLR) provides the runtime environment for compiled MSIL code. The CLR provides services including just-in-time compilation into native machine code, memory management including garbage collection, thread management, and security services.

Code that executes within the CLR is called managed code. Managed code relies on the CLR for its execution environment. Unmanaged code generally executes on the native hardware and performs its own memory management and other services. Microsoft has provided facilities to allow managed and unmanaged code to interoperate with each other.