3D viewers are software applications that allow users to view and interact with three-dimensional (3D) models on their computer or mobile device. These models can be created using various 3D modeling software tools, such as Blender, Maya, or SketchUp.

With a 3D viewer, users can rotate, zoom in, and zoom out on the model to see it from different angles and perspectives. Some 3D viewers also offer the ability to manipulate the model in other ways, such as changing its lighting, texture, or color.

In addition to static 3D models, some viewers can also display 3D animations, allowing users to see the model in motion. Some viewers also support virtual reality (VR) technology, enabling users to view the model in an immersive VR environment.

3D viewers are commonly used in industries such as architecture, engineering, and product design, where 3D models are used to visualize and communicate complex designs. They are also used in gaming, animation, and virtual reality applications, where 3D models are used to create immersive virtual environments.