XNA Framework - a set of software tools from Microsoft built on the .NET Framework, designed to develop, manage and run video games written using XNA technology for Windows, Xbox 360 and Windows Phone 7 platforms. The application can be useful for video game developers as well as for ordinary users, because the XNA Framework Redistributable is needed to run games made with XNA Game Studio on their computers.
XNA Framework allows you to significantly accelerate the process of developing computer games by combining different aspects of creating a game project in a single system. The framework also helps to avoid many technical difficulties in programming, for example, repetitive boilerplate code, and gives the opportunity to create games with high-quality 2D and 3D graphics and serious functionality.
All components of the XNA Framework are conditionally divided into four abstraction levels. The lowest level is the Platform, which contains native APIs such as Direct3D 9, XACT, XInput and XContent. The second level, the Core Framework, is platform-independent and is responsible for basic functionality: graphics, audio, input, storage, mathematical calculations and more. The third level, the Extended Framework, is a package of high-level classes. It's kind of a universal game engine. It provides the solution of typical tasks: import of textures and models from graphic editors through the content pipeline, initialization of graphic devices and so on. The fourth level is the game application itself, which is created by the developer. In addition, XNA includes some simple video games called Starter Kits, which can be used as templates for developing your own applications. Microsoft stopped developing XNA after version 4.0, so the framework receives no new features, but the 4.0 redistributable is still offered by Microsoft for games that depend on it.
The XNA Framework accelerates game development process by integrating various aspects of game creation into one system.