floor jack is a hydraulically-operated portable jack, mounted on
wheels, which is used to raise a vehicle a short distance off the
ground, especially when only part of the vehicle needs to be raised.
The lifting pad on the jack is positioned under the chassis of the
vehicle, at the manufacturer's recommended lift points, and the
jack handle worked with a pumping action. This forces fluid into
the hydraulic cylinder, which extends, driving the jack lift pad
upwards and thereby lifting the vehicle. Note that floor jacks are
not intended to support vehicles while people are working under
them. Jack stands are essential for this purpose.