Since cats are living creatures, they can experience emotions just like people do. If you happen to introduce a second cat to your home that already has one cat, there’s a chance the new cat might make the older cats jealous.
The key to dealing with jealousy is to spend time with all your cats. That way none of them will feel neglected. You should also introduce a new cat into a home gradually so the other cats can get comfortable with the other cat before actually facing it in person.