.NET is a free, open-source, cross-platform framework developed by Microsoft for building various types of applications. It provides a comprehensive set of tools, libraries, and runtime environments for developing and running applications on different platforms, including Windows, macOS, and Linux. JDK stands for the "Java Development Kit." It is a set of software tools and libraries that developers use to develop Java applications. JDK includes everything needed for Java development, from writing code to testing and debugging. Key components of JDK include: