How many types hydraulic systems there?

There are primarily two types of hydraulic systems: open-loop and closed-loop systems. Open-loop hydraulic systems operate without feedback and are typically simpler, used in applications where precise control is not critical. Closed-loop systems, on the other hand, incorporate feedback mechanisms for improved control and efficiency, making them suitable for applications requiring precise movement and pressure regulation. Additionally, hydraulic systems can be classified based on their design, such as single-acting and double-acting systems.