Since most of the information about the world enters our brains through our eyes, how that information is organized and displayed is really important for making a decision. Over the years we have made up standard forms of display--such as the metro map and the pie chart, to convey essential information quickly. This "table of tables" from Visual-Literacy is a great summary of many common examples. The tree to the right is one example.
Click on Periodic Table of Visualization Methods and move your mouse over the table.