This document provides a comprehensive analysis of peer-to-peer (P2P) networks, focusing on their architecture, types, and applications in data sharing. It categorizes P2P networks into centralized and decentralized models, as well as structured and unstructured systems, and compares popular P2P systems like Gnutella, Napster, and Fast Track. The research emphasizes the evolution, characteristics, advantages, and disadvantages of various P2P technologies.