A Chart is a graphical representation of the data in a report. This means, like a report, a chart has a base object. And like a report, a chart can contain fields from related objects. However, the chart can only include the fields shown in the chart's base report. If you want to add an additional field from the object you will either have to add the extra field to your existing report, or create a new report that includes the field.
There are many different types of chart available. Pick the type of chart that is responsible for the shape of the data you have.
To learn more about a chart's basic capabilities, click here .