“Data charts and diagrams are used when statistical data has to be presented in the most convenient and usable way. Visual charts are clear, visually appealing and easier to perceive than some simple enumerations or tables  mainly because users don’t have to analyze the meaning of presented facts, but can perceive main tendencies through the visual weight of the facts  directly.
You can create charts in graphic editors or use special applications (software or web-apps) which can help you to create your charts in few minutes. However, once you’d like to update an old chart, or create a new one, you have to run the application and create new images over and over again. That’s not flexible. Or maybe you just want to offer your visitors not a simple image, but a powerful dynamic chart.”