Hydraulics is a branch of science that deals with the behavior of liquids in motion and at rest. It focuses on the principles of fluid mechanics to design systems that use liquids to transmit power. Common applications include hydraulic lifts, brakes, and excavators, where fluid pressure is used to perform work efficiently. Mechanics is the study of forces and their effects on matter. It encompasses both statics, which examines objects at rest, and dynamics, which looks at objects in motion. Mechanics is essential in engineering and physics, helping to understand how structures like bridges and vehicles operate under various forces.