beam axle vs solid axle? what's the difference?

So on the roamer, d-series and the h-series. for the front suspension you have 4 choices; independent, off-road independent, beam axle and solid axle.

So what's the difference between beam axle and the solid axle?

 

My guess is that, more than likely judging by their wording and not looking at it myself because I am lazy, I would guess that Beam Axle is unpowered, and Solid Axle is powered.

 

yeah that seems to be the case

 

Yup, you're correct
<---Beam/Solid--->