Do hydraulics use liquid or water?

Hydraulics typically use liquids, which can be various hydraulic fluids, not limited to water. While water can be used in some hydraulic systems, especially in low-pressure applications, hydraulic fluids are often specially formulated oils that provide better lubrication, corrosion resistance, and temperature stability. These properties make hydraulic fluids more effective for transferring force and ensuring system efficiency in a wide range of applications.