Before you can create a chart, you must have data. The data is stored in cells within a worksheet. Typically, the data used for a chart resides on a single worksheet, but this is not a strict requirement. A chart can use data stored on another worksheet—or even in a different workbook.
A chart is essentially an object that Excel creates on demand. This object consists of one or more data series that are graphically displayed. The appearance of each data series depends on the selected chart type.
For example, if you create a line chart that uses two data series, the chart will contain two lines—each representing one of the series. The data for each series is stored in a separate row or column. Each point on the line is determined by the value in a single cell and is represented by a data marker. You can distinguish each line by its thickness, line style, color, or data markers.
A key point to keep in mind is that charts are dynamic. In other words, a chart series is linked to your worksheet data. If the data changes, the chart is automatically updated to reflect those changes.
After creating a chart, you can always modify its type, adjust formatting, add or remove specific elements (such as the title or legend), add new data series, or change an existing series to reference a different range of data.
A chart is either embedded in a worksheet or displayed on a separate chart sheet. It’s easy to move an embedded chart to a chart sheet—and vice versa.