Microsoft DirectX 11 is a collection of APIs (Application Programming Interfaces) for graphics and multimedia tasks in Microsoft Windows. Released in 2009, DirectX 11 introduced new features such as tessellation, multi-threading support, and Compute Shader. These features allowed for more realistic graphics and improved performance in games and other multimedia applications. DirectX 11 is backward-compatible with older versions of DirectX, ensuring that older games and applications can still run on newer systems. It is widely used in the gaming industry and has become a standard for Windows-based gaming. DirectX 11 also provides improved security features and better support for multi-core processors.