Dev Notes: World‐building - openly-retro/stellaris-machine-robot-expansion GitHub Wiki

These are the definitions of things in my mind:

Categories:

Biological: Procreates by cellular division or crystalline lattice
Mechanical: Procreates by constructing a separate, distinct form via alloys-based engineering

Species terms:

Robots: Non-autonomous, non-sentient, mechanical form running a specific program like "ship repair bot" or "food service bot". It cannot become sentient because it lacks a positronic brain.
Mechanical: Having a robotic or machine-like appearance. Runs a generalized program and can do all tasks. It can become sentient because it has a positronic brain. Biological species can "ascend" to become Mechanical.
Synthetic (Synth): Having a biological appearance. Its organs and functions are artificially created (lab grown or manufactured) but mimic the biological counterparts. It can become sentient because it has a positronic brain. Biological species can "ascend" to become Synthetic. Mechanical species could also theoretically transform themselves to become synthetic. Probably the best category that describes "artificial" life
Bio Robot (from this mod): Having robotic OR organic appearance. It is autonomous, self-programming, has a positronic brain. It is part synthetic, part mechanical. Machines and bio forms can recompose/ascend themselves to become this.
Machine: Having a robotic or machine-like appearance. Autonomous, self-programming, sentient. It doesn't have organs, it has components and modules which are not analogous (have no 1:1) to biological / synthetic organs, aside from positronic brains that have a wide range of designs.