Answer
The Common Language Runtime, or CLR, is the execution engine of dot NET that manages running applications, handling tasks such as memory management through garbage collection, exception handling, thread management, and security. The execution process starts when source code, written in a language like C#, is compiled into an intermediate language called CIL or MSIL, and when the application actually runs, the CLR's Just In Time compiler converts that intermediate language into native machine code specific to the computer it is running on, which is then executed directly by the processor.
// C# source code
Console.WriteLine("Hello");
// Compiled to CIL, then JIT compiled to native code at runtime
// This happens automatically when you run: dotnet runReal-world example A dot NET application written in C# runs correctly on any machine with the correct runtime installed because the CLR converts the same intermediate language into machine code appropriate for that specific processor at the moment it executes.