Hydraulic refer to liquids (e.g., water), electric refers to electricity and pneumatic refers to gases (e.g., air). They are different devices that can be applied to a robot drive.
Hydraulic, electric and pneumatic devices
Hydraulic devices refer to the technologies that involve the use of liquids such as oil or water.
Pneumatic devices refer to the technologies that involve the use of gases such as air.
Electricity devices refer to the technologies that involve the use of an electric field to produce a given outcome (e.g., motion in an electric motor).
A robot drive may exploit these different devices in order to perform specific functions.
Learn more about pneumatic devices here:
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