Object-oriented programming has been widely accepted and is being used almost religously in industry.  In order to be able to easily connect objects and their inheritence and classes, the .NET Framework uses managed code.  Managed Code runs in an environment called Common Language Runtime (CLR).  The CLR componenets are then transitioned into Microsoft Intermediate Language (MSIL) when compiled.  What is so special about CLR is that it allows the user to write in any supported language on the .NET platform and the code is interpreted into the MSIL and compiled the same.  This fundamental concept can be seen below.

The .NET Framework also provides automatic memory management.  This function is described as garbage collection.  If the CLR detects when a program is no longer using the memory, it recycles it.  There is no longer the need for checking for enough disk space for the program.  If disk space is not being used, it is recycled and freed up.