.NET Core and .NET Framework are distinct frameworks for application development, with .NET Core being an open-source, cross-platform successor enabling developers to create applications on multiple operating systems like Linux, macOS, and Windows. In contrast, .NET Framework is a proprietary Microsoft framework that primarily targets Windows applications. While both frameworks offer different libraries and functionalities, .NET Core is recognized for its enhanced performance, scalability, and compatibility for modern cloud-based applications and microservices.