Who is St. Peter from Catechism of the Catholic Church and what is their importance?

This was one of the original twelve apostles of Jesus Christ. He was viewed as the "rock" of the faithful, and the one upon whom, beyond Jesus himself, the Church could be founded. He comes up early in the book, in reference to the Pope. Peter was the head apostle. Through hand-picked succession, the present Pope is an apostle that is directly in the line of Peter.