Keith Marischal is a person, just like you and me! He might seem like a stranger to you, but he's just someone who has a name.
Sometimes, we use people's names to talk about them or identify them. For example, if your name was Sally, your teacher might say "Sally, can you come up and grab this pencil?" That's how names work!
Keith Marischal is one person's name. That's all there is to it!