A hierarchy graphically represents a series of ordered groupings of people or things within a system. By using a SmartArt graphic in Excel, Outlook, PowerPoint, or Word, you can create a hierarchy and include it in your worksheet, e-mail message, presentation, or document. 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.