1. Introduction -- 1. Introduction -- I. Peer-to-Peer: Notion, Areas, History and Future -- 2. What Is This “Peer-to-Peer” About? -- 3. Past and Future -- 4. Application Areas -- II. Unstructured Peer-to-Peer Systems -- 5. First and Second Generation of Peer-to-Peer Systems -- 6. Random Graphs, Small-Worlds and Scale-Free Networks -- III. Structured Peer-to-Peer Systems -- 7. Distributed Ha…