Blender is a free and open-source 3D graphics software tool used for modeling, animation, rendering, video editing, and creation of interactive 3D applications including video games. It supports Windows, Mac OS, and Linux and features modeling tools, animation tools, material and texture systems, simulations, scripting via Python, and a customizable interface. Blender can be used to create 3D graphics, animations, games, visual effects, interactive 3D applications, and experimental films.