Object Components (or 3D Objects) are a sub-Family of all Components and are used to render 3D scenes with the Render TOP: The most common are the Geometry Component containing the 3D shapes to render, the Camera, Light and Null components.

There are sixteen 3D Object component types, found in the left column of the Components page of the OP Create menu:

Python Objectsedit

"Objects" are used in the context of Python scripting in TouchDesigner.