SketchUp is 3D modeling software that was originally developed in 1999 and is now owned by Trimble. It allows users to create 3D models of buildings, furniture, landscapes and more. The document discusses SketchUp's capabilities such as basic 3D modeling, applying materials, organizing objects, layout drawings, geo-location features, dynamic components, and using it for construction documentation and collaboration. It also provides a brief history of how @Last Software created SketchUp and it was later acquired by Google and then Trimble.