They are covering you and the things around them with pheromones which come from glands on their face and head.
Kitten keeps rubbing face on floor.
Cats typically display head bunting toward other cats dog companions and humans.
Cats rub on walls furniture shoes and even other things lying around on the floor.
Cat to cat head bunting and allorubbing are reserved for cats who already have a familiar and friendly relationship.
Rubbing is a natural feline marking behavior.
Lip rubbing is often reserved for marking objects.
When your cat engages in head bunting or head rubbing he is placing his scent there as a social and affectionate gesture.
This tells other cats that they ve been there claimed their spot and have already marked you so other cats need to back off.
Cats have scent glands located in their cheeks forehead chins and a the base of their tail and rubbing up against people other cats and objects is a form of marking without being a territorial action like spraying sackman says.
Head butting is an over the top version of face rubbing.
If the cat knows you already or is just really enthusiastic about people he may not wait for a polite greeting.
When your cat rubs its head and cheeks on the floor it can be leaving its scent markers on the house and over your feet.