If a cat rubs on a object, then it is adding it's sent to it, as a way of making the thing it's teritory.
If it rubs it's face on you that is a sign of affection and love.
A cat does this to mark their territory or (if to a person) they are responding; telling you that your theirs.
Cats lick their paws to groom themselves and keep clean. They rub their heads to mark their territory with scent glands located on their face.
Cats rub their head on your face as a way to mark you with their scent. It's a sign of affection and ownership, as they are claiming you as part of their territory. It's also a way for them to show trust and bond with you through scent exchange.
Cats may rub their butt on objects to mark their territory with scent glands located around their anus. This behavior leaves behind their scent, which is a way for them to communicate with other animals in the area.
Cats will rub their backs or bodies on you when being petted to transfer its scent onto you.
If you mean rub heads, it's a way of showing affection or a need for attention.
When we rub two objects together then heat energy is generated.
Cats lick their paws to clean themselves and then rub their head to spread their scent, marking their territory and showing affection.
Gain or lose
Cats have bald spots in front of their ears because that area is where scent glands are located. When cats rub their faces against objects or people, they are marking their territory with their scent. This behavior can cause the fur to wear away over time, resulting in bald spots.
Cats lick their paws to groom themselves and keep clean. They rub their face to mark their territory with scent glands located on their cheeks.
Friction is the resistance to motion that occurs when two objects rub together. It is caused by the interactions between the surfaces of the objects, which create a force that opposes the motion.