Right Dennis, The chart translates data (often percentages) into images. A chart can do that or many other things with other styles of information. A timeline is an example of how this would be different from a chart. It organizes any information into many forms of visual explanations.

A chart is a detailed diagram. You chart your life and your life is no diagram.

A chart is a type of diagram, but all diagrams are not charts. Take a look at http://en.wikipedia.org/wiki/Diagram which illustrates the difference very well.