You can see the whole system works in an organized way. Of course if one item is removed, it is replaced by other items. The condition is that item must be in demand.
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 .