A caption is a short descriptive or explanatory text, usually one or two sentences long, which accompanies a photograph, picture, map, graph, pictorial illustration, figure, table or some other form of graphic content contained in a book or in a newspaper or magazine article.
In technical writing, however, the caption is usually positioned above a table.
In magazines and similar publications, a caption can be placed opposite the picture or sometimes on top of the picture itself.
[4] In technical writing, the caption usually contains the number of the figure or the table, as well as lengthy and complete details about the figure.
The source of the information in a caption is usually cited at the end of it.