Wikipedia: When the data appearing in a chart contains multiple variables, the chart may include a legend (also known as a key). A legend contains a list of the variables appearing in the chart and an example of their appearance. This information allows the data from each variable to be identified in the chart.
Wikipedia: One of the more important uses of text in a graph is the title. A graph's title usually appears above the main graphic and provides a succinct description of what the data in the graph refers to.
ChartWord: When the data appearing in a chart contains multiple variables depicted in different colors, the chart title and legend can be integrated to allow the data from each variable to be identified...
from Of Two Minds blog
ChartWord remix
