Commenting is the activity of adding information to a piece of data, usually in a way that separates the data to which the comment is attached and the comment. It usually serves to express some opinion, to add contextual information, or to engage in communication or collaboration with others about the object commented on. This is different from Annotating (as defined here) which refers to adding descriptive or explanatory information to sections of an object with the aim of making inherent qualities, structures, or meanings of that section explicit.