A standard button
Note: the above is a Windows 10, Chrome default styling, by applying the right styling virtually any look and feel can be achieved.
The elements value will be used as the label of the button on the screen (The “Button” in the above image).
If a Select Action node attached, then when selected the items will be treated as an action graph. If the value of the Select Action is Action, then the action is followed, this may be to enable/disable another control, change some on screen data, invoke a model etc.
For a hover over popup box (usually referred to as a title), attach a Hover element to the button with the desired text.
Any attached CSS element will be applied.