There are several reasons why cats lick their owners' hands. Generally speaking, the main explanations include the following:

1. Expressing affection: When we find our cats licking our hands, they are mainly trying to express their love and affection for us, their owners.
2. Seeking attention: When cats are bored, they will often lick their owner's hand to attract their attention and get interaction.
3. Leaving a scent: Cats use saliva to mark their territory and relatives, so they will lick their owner's hands to assert their dominance.
4. Seeking food: Cats often lick their owners' hands, whether intentionally or unintentionally, possibly to increase their chances of getting food.