Creating a report - what is the Chart Widget Icon from the tool bar

If you are talking about the chart button, that is for you to choose between pies or bars.

Please check these 2 guides for more information:

http://www.jotform.com/help/326-How-To-Create-Form-Reports-in-JotForm

http://www.jotform.com/help/187-How-to-Create-a-Visual-Report-with-your-Form-Submissions