There are several types of 3D models, each serving different purposes. The most common types include polygonal models, which are made up of vertices, edges, and faces, and are widely used in video games and animations. Another type is NURBS models, which use curves to create smooth surfaces, making them ideal for automotive and industrial design. Another category is sculpted models, created using digital sculpting tools that allow for detailed and organic shapes, often used in character design. Lastly, parametric models are defined by parameters and can be easily modified, commonly used in engineering and architectural design.