With the change in sit out rules they’re all common now. Why does it matter? Each person has to take their own path. The objective is to have the same end result.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .