Both. Lippert makes a six point leveling system that is hydraulic, and it works very well (in my experience with an Evergreen Bayhill). We now own a Seismic with the other Lippert system, which Jayco advertises as a six point leveling system. It is not. The Lippert system with the electric jack uses the four corner jacks to (theoretically) level the camper and then lowers the middle jacks for stabilization. There is no way to lower the middle jacks manually. So far, if the trailer is already sitting level, it will go through its cycle just fine, but if the trailer is not already level, the system faults, quits, and then won't lower the stabilizing jacks.
I had the hydraulic Lippert system level my Evergreen from 4 degrees off level side to side. It had to pick the lower wheels completely off the ground, but it did it. The electreic Lippert system will not level my Seismic from 1.8 degrees off level side to side. If you can, stay away from this system. Get the hydraulic system if it is an option.