In This book introduction to Mobile ad hoc network and there is also some challenge for Ad-hoc network like Routing, Security and Reliability, Quality of Service (QoS), Internetworking, Power Consumption. Among these problems routing and security is main problem with ad-hoc network that is discuss in book and also focus prior knowledge about network routing protocols and various security issues are present in wireless network like black hole attack, wormhole attack and eavesdropping and its related quantitative performance metrics.