An annotation, as opposed to a label, is defined as a single piece of meta-information, such as an object (e.g. polyline, bounding box) or image category (e.g. sunny, outdoors, etc.) used to describe raw data. For example, in a raw (unmodified) image of a forest, you may choose to put a bounding box around individual flowers, or run a polygon segmentation on trees, or categorize the image as "forest". Once your annotation project is completed and you would like to export them, the export result will contain all of these annotations and their corresponding classes.