Now days Peer to Peer systems have become an important part of the internet and millions of user have been attracted to use their structure and service. Peer to Peer network systems are distributed systems that provide different characteristic then client server system. Peer to Peer network has widely populated among the internet user as well as computer professionals. Some of the benefits of a Peer to Peer approach include: improving scalability by avoiding dependency on centralized points; eliminating the need for costly infrastructure by enabling direct communication among clients; and enabling resource aggregation. In this Book, Survey and comparison of different Peer to Peer architecture has been introduced. Detailed Survey and performance comparison of structured (Chord, Kademlia) protocol has been done and unstructured Peer to Peer Protocols (Gnutella, Napster, and BitTorrent) have also been studied. Finally Chord and Kademlia have been simulated and analyzed for detailed performance comparison.