Build Your Own SLA/SLS

I'm trying to get a general top-level understanding of which parts are responsible for what. I know from fooling around with Marlin that it defines axis lengths, steps/mm, motor speeds, and a host of possible peripherals.

The CW software then slices the object, renders the G-Code and communicates that to the board, so the Firmware must also interpret the commands from the software, or am I off the mark?

Thanks!