[carpoor]

Sorry, worked in the industry off and on for years.

In a nutshell, stem wall - they build a wall the perimeter of the home. Then fill the center with fill dirt and tamp it down. They do a compaction test, ok it. Then pour a slab on top of it. The top row of blocks are chair blocks, and stick up above the fill dirt. Giving a guide of where to pour up to.

Monolithic - they form it up. Then install wire mesh and rebar. The concrete is fiberglass reinforced.

Both methods use poured footers for a solid foundation. But, you can clearly see why I prefer monolithic. That dirt they fill and tamp down in stem wall settles after the slab is poured. It's simple physics, and common sense.