The Common Language Runtime (CLR), the virtual machine component of Microsoft .NET Framework, manages the execution of .NET programs.
[1] The CLR provides additional services including memory management, type safety, exception handling, garbage collection, security and thread management.
CLR implements the Virtual Execution System (VES) as defined in the Common Language Infrastructure (CLI) standard, initially developed by Microsoft itself.
A public standard defines the Common Language Infrastructure specification.
[2] During the transition from legacy .NET technologies like the .NET Framework and its proprietary runtime to the community-developed .NET Core, the CLR was dubbed CoreCLR.