Instances amount on Roblox renderer stats

Help and Feedback Platform Usage Support
#1

Im not sure on what category this belongs to so i just put platform usage,

The Instances amount right here
image

What does it mean?
Also whenever I add parts to the game, the instances amount goes up and when i delete that part, the instances do not go down, im just confused about this, and how it can be used to optimize, or whatever it is, anything helps!

#2

The instance count is the total amount of instances in your game. It should be a very large number but should not exceed 20 million.

Because you kept it in memory. Calling Destroy on it might make it go down.

#3

but the thing is i stop the game and i replay it so there are no parts