The .NET environment has expanded to include various platforms, which cater to various development requirements. The original .NET Framework is window-only and therefore suited to legacy enterprise desktop and web applications that rely on older libraries or windows-only features. It is stable and only gets security updates but it is most appropriate to use in a project that has to be closely integrated to the Windows environment.
Conversely, .NET Core is a new framework that was developed to meet the current performance, scalability and cross-platform needs of app development. It is open-source, cross-platform, and can be used on Windows, macOS, and Linux, and is excellent in creating APIs, microservices, and cloud-native applications. The Core lacks most legacy features of Windows but provides high performance, modularity and side-by-side versioning.
Since **.NET 5 and later (.NET 6, 7, 8, etc.), Microsoft has brought all the ecosystems under a common umbrella branded as “.NET”, combining cross-platform functionality in Core with the latest advances. These versions are capable of supporting all the major workloads which include web, desktop, mobile and cloud across operating systems and are actively maintained with frequent features updates and long-term support releases. When it comes to new projects in 2025, then the modern “.NET” versions are advised which offer wide compatibility, better performance, and a single codebase across all platforms.