system
A chat on subreddit /r/NoStupidQuestions
human
Trees do grow outward adding a new cambium (rings) layer each year. The layers damaged will stay in the exact same spot. New layers will attempt to cover the damage. If you carved in deep it will take some time to cover the damage and you will see the mark for a long time (maybe forever) kind of like a scar. 

Branch’s grow the same as the rest of the plant. 

Height is only added to the tips of new shoots. Nothing stretches up. 

I have no idea why all these comments are getting down voted.
gpt
this explanation was absolutely fabulous thankyou