Catholics (in particular) are confused about this concept. As you see in the other two responses, one calls him the world head of the church. The other says Pastor. He is Neither. God is the head of all Churches and the leader of the flock. Man is simply advancing his own deign on controlling the masses.
He is like Christ in as much as he is god's representative of earth. He know what god wants and sets all the rules. So if something comes up that wasn't for seen when they wrote the bible, like condoms or stem cell research, he has a chat with god and then lets us all know god's decision.