What is this connection called and what is it good for?
That doesn't look like a connection to me.
Is more the place for a so-called "Kensington lock"
I think this is for a lock.
Kensington lock, so you can secure your laptop against theft with a wire
e.g. Something like that: https://www.reichelt.de/laptopschloss-schluessel-1-8-m-silber-n-nblkk1002me-p242638.html?PROVID=2788
The symbol and shape indicate a Kensington socket for a Kensington lock.
Like with a bicycle, you can "chain" your laptop and secure it against theft.