What are carbon pools? Eli5

In a conversation with Andrew O'Reilly-Nugent, Namya, and Shola Ogunkelu, Andrew asked us to describe complex topics with the help of analogies and lead by an example.

He said,

"I find a practical way to describe complex topics is by using analogies. One I really like about carbon pools is to think of a bucket being filled by a tap, with a hole in the bottom.
The water level of the bucket is determined by the rate of water flowing in from the tap, minus the amount of water flowing out from the bottom. If we increase the inflow, without also increasing the outflow, the water contained within this bucket will rise. Alternatively, if we increase the outflow, without increasing the inflow, water levels will drop.
FLINT models carbon pools in terms of stocks and flows - does this analogy help you visualise what a pool represents?"

This was one of the best analogies I came across for carbon pools and I think it would have been selfish to not put it out there.