Hydraulic power remains a fundamental technology in mobile machinery because of its high-power density, robustness, and ability to perform demanding functions under widely varying operating conditions. At the same time, increasing requirements for energy efficiency, reduced emissions, improved performance, and advanced control are driving the integration of hybrid and electrified technologies into modern mobile machines. This book provides a practical and application-oriented reference to hydraulic systems and emerging technologies used in mobile equipment. It is intended for engineers, technicians, educators, and other industry professionals involved in the operation, maintenance, troubleshooting, and design of mobile machines. The first four chapters of the book cover conceptually the systems commonly encountered across mobile machines such as hydrostatic transmission, control blocks, steering systems, fan drive systems, hybrid systems, and mobile machine electrification. It then examines sixteen categories of mobile equipment, including construction and road-building machinery, aerial work platforms, material-handling equipment, cranes, mining equipment, trucks, agricultural machinery, tunnel-boring machines, and selected aerospace, marine, military, and railway applications. Each application chapter introduces the equipment and its major hydraulically driven functions, supported by hydraulic circuit diagrams and representative industry examples. Hybrid and electrified configurations are also discussed where applicable, providing readers with insight into both established hydraulic solutions and evolving mobile-machine technologies.