To edit the contents of a title, click the chart or axis title that you want to change. To edit the contents of a data label, click two times on the data label that you want to change. The first click selects the data labels for the whole data series, and the second click selects the individual data label. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.