This book covers different topics from UAV-s and drones - such as design and development of UAV-s, trajectory control techniques, small drones and quadrotors, and application scenarios of UAV-s and drones. Section 1 focuses on design and development of UAV-s, describing design and development of a fly-by-wireless UAV platform; review of control algorithms for autonomous quadrotors; central command architecture for high-order autonomous unmanned aerial systems, and quadcopter design for payload delivery. Section 2 focuses on trajectory control techniques, describing development of rescue material transport UAV; railway transport infrastructure monitoring by UAVs and satellites; assessment of UAV based vegetation indices for nitrogen concentration estimation in spring wheat; research and teaching applications of remote sensing integrated with GIS: examples from the field, and development of drone cargo bay with real-time temperature control. Section 3 focuses on small drones and quadrotors, describing neural network control and wireless sensor network-based localization of quadrotor UAV formations; navigation of small-class unmanned aerial vehicles; modelling oil-spill detection with swarm drones, a survey of modelling and identification of quadrotor robot, and visual flight control of a quadrotor using bioinspired motion detector. Section 4 focuses on application scenarios of UAV-s and drones, describing rescue material transport UAV; railway transport infrastructure monitoring by UAVs; UAV based vegetation indices for nitrogen concentration estimation, research and teaching applications of remote sensing integrated with GIS, drone cargo bay with real-time temperature control.