3D modeling is the process of developing a mathematical, wireframe representation of any three-dimensional object. The modeling process of preparing geometric data for 3D computer graphics is similar to plastic arts such as, sculpting.
Animation refers to the temporal description of an object i.e., how it moves and deforms over time. Popular methods include key framing, inverse kinematics, and motion capture, though these techniques are used in conjunction with eachother. Physical simulation is another way of specifying motion.
Rendering is the final process of creating the actual 2D image or animation from the prepared scene. Several different and often specialized rendering methods have been developed. These range from the distinctly non-realistic wireframe rendering through polygon-based rendering, scan line rendering, ray tracing, and radiosity.