I would like to clarify a doubt

I recently purchased a jump-starter system, and the manual mentions terminology regarding how to connect it.
It refers to a system with negative ground and a system with positive ground. Could someone explain what each of these terms means? Thank you very much for your attention.

That "terminology" refers to how the electrical system is connected in the car.
But the correct way to connect it is from the jump starter's positive terminal to the car battery's positive terminal
, and from the jump starter's negative terminal to the engine ground.

Engine ground is any metal part.
Remember:
positive = red wire = (+)
negative = black wire = (-)