"Here's what happens when you unfriend someone

"Tony, it looks like you recently unfriended someone. This means that they'll no longer be able to see the posts you share only with your friends, and you won't be able to see theirs. Don't worry, they won't know that you've unfriended them.

"— The Facebook Help Team"

What does "they won't know that you've unfriended them" mean? I still show up to them as a Friend?