Generally, UV coatings are used to boost the aesthetics of a print, and spot gloss is the most common application.
With UV coatings, you can get higher gloss and rub resistance than aqueous coatings, but if you need an edge-to-edge application, aqueous is a cheaper option.
Protects product from scuffs and scratches
Higher gloss options than aqueous or varnish
Ink rub resistance
Spot and flood coating options
No solvents emitted in curing process (cured with UV, not heat)
Requires more energy to dry than aqueous coatings
Resists additional imprinting (i.e. writing with pen or pencil)
More expensive than aqueous coatings
Can crack more easily when scored or folded (since the coating is thicker/harder)
Can emit an unpleasant smell, but low odor options are available
Specialty process: Fewer factories have this equipment