These are special finishing you can apply to specific areas on your print to make it shinier. For example, you can apply the UV varnish to your logo, or some specific text to make it pop. The overall idea is to create a contrast between the paper stock being used and the extreme glossiness or vividness of the varnish.
Spot UV is applied after the actual design has been printed in the regular fashion. UV gloss has a special kit that locates the exact position for the varnish and applies it before bombarding the varnish with UV rays to finish the process. The result is a very special printed product.
You don’t need to do anything special to your design when anticipating the use of UV varnish. It is a matter of specifying exactly which sections of print work are to be covered. Technology takes care of the rest.