What is "debris"?

[kerbiloid]

What exactly is "debris" in terms of KSP?
(By default limited at 250 pieces.)

I thought it's everything without a command pod. So, a "debris collector" deletes all of them except last 250.
So, we can't just drop something on ground and take it back a year later. It likely will be destroyed.

But in the Breaking Ground there is equipment to be installed on ground.
It doesn't have a command module in cfg, only ModuleGroundExperiment.

Does it mean that there are some modules which define a part as non-debris, making it permanent?
So, one can put a whole minefield of this part instances.

Or this equipment is still the debris, and crashing a big rocket aside would make this equipment disappear by adding 250 more debris?

Thank you in advance!

Edited January 5, 2020 by kerbiloid

[Benjamin Kerman]

As far as I can tell, it's just a label applied to a vessel by the game that determines what _type_ of vessel it is. The game looks at the parts and determines if you can control it or not, ect, and then you can reassign the label in the tracking station I believe.

So a piece of equipment that you put down might be considered debris, but if you change the label in the tracking station, it won't be destroyed by the "garbage collector". However, I doubt that if you have a research station or equipment like this that the game would auto assign it as debris, especially if it's meant to be left alone.

tl;dr: game probably smart, will see if vessel is supposed to be there, if not it gets collected, if it's good it stays