There's nothing wrong with asking questions that seem to be simple, such as what is the difference between motorhome levelers and stabilizers, especially if you're a newbie. Experienced rvers expect some questions to be head-scratchers, not because they are complicated but because they are about things that seem self-evident. Such is the case with this one: what is the difference between motorhome levelers and motorhome stabilizers? At first glance this question doesn't make sense, but after thinking about it, I can see why it would be asked.
Here is the answer: Stabilizers have a different function than levelers, but to those who haven't had some experience with both they seem to do the same thing. The problem is that on motorhomes it is sometimes sufficient to let the levelers also do the stabilizing. If the motorhome is level and this leveling has been done with the hydraulic jack system, then chances are it will also be stable. When we say a motorhome (or any rv for that matter) is stable we mean that it doesn't shake or move in any way when you walk around inside. So it is possible to level the rv and find that it is stable, at least sufficiently so for the owners.
But stabilizers cannot be used to make a motorhome level. Stabilizer jacks are normally placed at the four corners of a rig, or at least as close as you can get to those areas. The jacks are tightened in place and keep the rv from bouncing or swaying, but they are not strong enough to lift the rv to make it level. So the difference between levelers and stabilizers is that levelers can also stabilize the motorhome, but stabilizers cannot also be used to make it level. Generally speaking, the more of the coach body there is behind or in front of the wheels, the more need there may be for stabilizer jacks.