Final answer:
The 'legend' in a chart identifies the colors or patterns assigned to various data series, aiding in the interpretation of the graph.
Step-by-step explanation:
The element that identifies the colors or patterns assigned to the various data series in the plotted area of a chart is known as the legend. When data is represented graphically, a chart's legend serves as a key to help the viewer discern which graphical elements correspond to which data series. For instance, in a bar chart that tracks monthly sales data, the legend would indicate which color bar represents each month. In the case of a scatter plot, the legend could show what kind of symbols or colors represent different groups of data points. Understanding the legend is crucial for interpreting the data accurately and drawing meaningful conclusions.