If you choose Overrides When Applying Style from the Object Styles panel, clicking an object style clears overrides by default. If this option is not selected, you can Alt-click (Windows) or Option-click (Mac OS) the object style to clear overrides while applying the style.

You can also drag an object style onto an object to apply the style without first selecting the object.

If a group is selected when you apply an object style, the style is applied to each object in the group.

Once you apply a style, you can apply other settings to the object as needed. Although you may override a setting defined in the style, you do not lose the connection to the style.