.NET Core is a free, open-source, and cross-platform version of the .NET Framework. It is a modular, high-performance runtime that can be used to build console, desktop, web, and mobile applications. It is built on top of the Common Language Runtime (CLR), which is responsible for managing the execution of code and providing services such as memory management and security.
.NET Core includes a set of core libraries, called the “CoreFX,” that provide a wide range of functionality, including collections, I/O, networking, and more. It also includes a runtime environment, called the “CoreCLR,” that is responsible for executing code and providing services such as garbage collection and JIT compilation.
The .NET Core runtime is designed to be lightweight and modular, which allows developers to include only the libraries and features that are needed for their specific application. This makes it an ideal choice for building applications that need to be deployed on a variety of platforms or have specific performance or resource requirements.
ASP.NET Core, which I mentioned earlier, is built on the .NET Core runtime and is an open-source, cross-platform web framework for building modern web applications.