An Annotation is a Resource. An Annotation usually has a single Body, which is a comment, a scribble, a video an image a sound, and a Target that the Body is somehow “about”. The Annotation could contain also additional descriptive properties.
Example Use Case: Gaelle has written a note that makes a comment about a particular movie shot. Her client application creates an Annotation with the note as the body resource, and the movie shot as the target resource.