What Do Buildings Stand On?

You see all of these apartment buildings around you; they don't just simply stand on leveled floors.
They stand on something called helical piles! Now I am still learning more about structural engineering,
so it may vary from building to building but I guess this is a cool thing and probably worth sharing.
So, helical piles are pillars that the building stands on.
The first thing done is a drill drills a hole into the ground until it reaches rock and then concrete is poured into that hole creating a helical pile.
Now there are definitely many more details to this but I am not a structural engineer, so I still have to learn all of those cool details.
Then caps will be placed on these piles (pile caps). Then your building will be placed on top of that!
Now that is pretty cool and a lot more things go in such as piping and wiring.
So, there are a lot more details and the process is much more complicated and I really want to learn that process!