Not sure if help is still needed, but here's the answer.
Chart: A chart is a visual presentation of numerical information, often displayed in the form of graphs or tables to make data more accessible and understandable.
Diagram: A diagram is a drawing that illustrates how an object or process works, often used to clarify complex concepts or systems through visual representation.
Side bar: A side bar is a section in a document or webpage that includes supplementary content, such as additional information, related resources, or context, to complement the main text and provide further insights for the reader.
Hope this helps! :)