"View claimed family" - what exactly does that mean?

When you watch the public profile of any deceased person and click on the action button you get in the dropdown a point "view claimed family". What exactly does that mean? Or to put it another way: how can a person who is not entirely or maybe very, very, very, very, very far away related, who has neither added the profile nor is a manager of it, claim my dad's direct cousin as family? I was surprised when I saw this, and I would like to be clear about the functions here. "Claiming" so far I understood as "someone makes a profile for a living person on here and invites that person, and as soon as that person has signed up, that profile is claimed and the original profile creator no longer has any control over it." What cannot happen with dead persons, of course. So, what does "claimed family" mean and how do you claim?