1. A hydraulic press is a type of hydraulic machine, which uses oil to transfer pressure. There are various types of hydraulic machines that can transfer pressure using grease or water, etc. Most hydraulic machines utilize oil for this purpose.

Hydraulic presses, a type of hydraulic machine, are mechanical devices that use specialized hydraulic oil as the working medium. They are powered by hydraulic pumps, which force the hydraulic oil through hydraulic pipelines into the cylinder/piston. Inside the cylinder/piston, there are several sets of mating seals, each at different positions, all serving to seal and prevent the hydraulic oil from leaking. The hydraulic oil circulates in the reservoir through a one-way valve, causing the cylinder/piston to reciprocate and perform mechanical actions, thereby serving as a productive force.

3. A hydraulic press is a machine that uses liquid as the working medium, made according to Pascal's principle, for transmitting energy to achieve various processes. Generally, a hydraulic press consists of three main parts: the machine itself (the main unit), the power system, and the hydraulic control system. The classifications of hydraulic presses include valve hydraulic presses, liquid hydraulic presses, and engineering hydraulic presses.