I have a question: First in a series

In what could be a start of a series, I am going to ask a question looking for a semi-techo explanation without the right vs left emotion.

Today's topic: Carbon Trading

I have not really been following the horse trading that is carbon credits and the associated ETS.

Can any of my readers explain how this trading bit works? Or direct me somewhere without the emotive Gorebull crap with a half decent explanation of the process.

The way I see it so far is:

When I grow some grass or trees, plants doing their thing lockup some carbon from the sky, some are better at it than others. Apparently locking up carbon is good for me. God knows why.

When I chop down the tree or cut the grass, to me the carbon is still locked up, but can be possibly readily unlocked by me burning the wood or my cows eat the grass/hay. At that stage the locked up carbon is unleashed on our unsuspecting planet.

So how does the horse trading in carbon get into the process?