Quick answer: Your cat licks you as a sign of affection and bonding — it's treating you as part of its social group, the same way it would groom another cat.
Cats groom each other — called allogrooming — as a way to bond and reinforce trust. When your cat licks you, it's extending that behavior to you. It's one of the clearest signs your cat sees you as family.
Some cats lick to get attention, out of learned habit, or because they're attracted to the taste of salt on your skin. Stress and anxiety can also trigger repetitive licking in some cats.
Occasional licking is normal. If it becomes constant, compulsive, or is accompanied by signs of anxiety — hiding, excessive grooming of themselves, or changes in appetite — it may be worth discussing with a vet.
Licking is almost always a compliment. If it bothers you, redirect with a toy instead of pushing your cat away — rejection can confuse them.