Noob question about NPRs when creating a new game

[Foolcow (OP)]

It looks like there are two different parameters for creating NPRs in the New Game screen.

First, on the left side, there is the Non-player Race Generation Chance.

On the right, there is a field called "number of computer controlled empires" which defaults to 1.

What is the difference between NPRs created from the generation chance and those created from the "empires at game start" field?

[voknaar]

From what I have read myself around the forums, the default NPR starts off when you do, and has basic transnewtonian tech (whether or not you choose to go for a conventional start). Any other NPR is spawned according to the NPR spawn chance set at the beginning of the game. You can trigger a NPR spawning or the default NPR will.  Spawned NPR's can have very low tech or possibly higher.  They also can explore and do all the things the Default NPR does as well. As such Spawned NPR's can create other NPR's as they themselves explore. Thats the basics of it anyway.