3D Warehouse is an online platform that allows users to upload, share, and download 3D models. It is primarily associated with SketchUp, a popular 3D modeling software. Users can find a wide variety of models, including furniture, buildings, and landscapes, which can be used in their own projects. The platform is user-friendly, making it easy for both beginners and professionals to access a vast library of 3D assets. Models can be searched by categories or keywords, and users can also contribute their own designs, fostering a collaborative community of creators and designers.