Smooth Preview
Wireframe Overlay
Just easy access to wireframe overlay toogle.
Smooth
Turn on the Viewport Display and Render Display of the Subdivision Surface modifier of the selected object.
Also apply shade smooth to the selected objects.
If subdivision surface modifier is not found in object, it will create one instead.
Normal
Turn off the Viewport Display and Render Display of the Subdivision Surface modifier of the selected object
Also apply shade flat to the selected objects.
If subdivision surface modifier is not found in object, it will create one instead.