Checking the box for "Show ToolTips" will show pop up explanations when hovering the mouse cursor over most items. Unchecking the box will turn off this feature.
Hovering over filenames in the Conversion List will show a ToolTip with the full path and filename. This makes it easier to keep track of which files you are processing especially if they are coming from different locations and have similar or the same names.
Hovering over the text box for "Output converted files to:" will always show a ToolTip with the selected output location. This is in case the path is too long to fit into the text box. You may also click in the text box and scroll to the right.