Hydraulic equipment and components use an incompressible fluid to transmit power, motion, and force. They are used in applications that require significant amounts of power, but lack access to other power sources (such as electricity). Unlike pneumatic systems, hydraulic lines are less prone to explosions. Fluid power systems are susceptible to cold weather problems such as freezing, however. Although some hydraulic fluids are water-based, petroleum-based fluids and synthetic fluids are also available. Some of these products for hydraulic equipment and components are fire-resistant or supplemented with rust inhibitors, anti-wear agents, and other additives.

Hydraulic equipment and components derive or produce power via fluid pressurization, and use pressurized lines to move the liquid and impart power. As stand-alone systems, hydraulics are often used to provide mobile power for trucking, construction, and heavy lifting applications. Hydraulic equipment and components are also used with industrial machinery such as molding and die casting equipment. Hydraulic systems may serve as the main power source or support and drive implements such as grippers. Suppliers of hydraulic equipment and components may also manufacture specialized hydraulic lifts for ski areas and marinas.

Hydraulic equipment and components include valves, switches, cylinders, pumps, hoses, unions, and fittings. Hydraulic valves are designed to contain and transfer the flow and pressure of hydraulic fluid. Hydraulic pressure switches open or close electrical contacts when set under pressure. Hydraulic cylinders are single-action or double-action devices with specifications such as maximum stroke. Hydraulic pumps are designed to deliver pressurized fluid flows to an outlet. Hydraulic hoses are typically flexible and often reinforced. Hydraulic unions and hydraulic couplings are designed for use with hydraulic hoses, and include quick couplers and hydraulic fittings.

Categories of hydraulic equipment and components include hydraulic reservoirs, valve actuators, pressure intensifiers, and hydraulic accumulators. Hydraulic reservoirs are designed to maintain the pressure of hydraulic systems at a specific value. Hydraulic valve actuators convert fluid pressure into linear or rotary motion. Pressure intensifiers, as their name suggests, are designed to increase the pressure of hydraulic oils. They differ from hydraulic pumps in that intensifiers can increase but not decrease the pressure of a normally-pressurized fluid. Hydraulic accumulators are used to store energy, absorb shock, eliminate noise, and counter-balance loads. Other types of hydraulic equipment and components are also available.