When you point to a style in the task pane, a ScreenTip lists all the details of the style. In the picture, all the formatting included in the Normal style is spelled out.
About the Normal style: When you click the New Blank Document button in Word, Normal is the default paragraph style in the document. It's the style for the document's body text, but it's also the basis for many other styles (see next tip).
Caution Anytime you click a style in the task pane, it gets applied in the document. So, if you don't mean to apply a style, take care that you only point—rather than click—to see the ScreenTip, and that you use the scroll bar to scan the list of styles rather than clicking the styles themselves.