What is Windows animation scale?

My **Samsung J3 (2016)** running **Android 7.1** used to sometimes lags while playing games (And also, FPS is bad). I read many posts and articals about speeding up my phone. I saw that you can improve its performance by going to **Developer options > Windows scale animation** and replace x1 with x0.5 or Off. ***Question is***, what those that affect? Those a higher setting make it run smother, better FPS? What happens when its at a lower or higher setting? That setting helps my phone, but I would like to know more about that setting.