What exaclty is, and how does one practice/improve trigger control?
From what I'm reading, I gather that trigger control means proper placement of the finger on the trigger, followed by a slow squeeze until the round fires. The squeeze is less like wrapping your finger around the trigger a squeezing it tight as if to criush it, and more like letting the pad of the finger move the trigger straight backwards. Almost as if one were pressing the trigger against the front of thr grips. One should not "pull" the trigger in a jerking motion. one should press the trigger backward.
Is that a good description?
I think that's a fine description. The only thing I would add is that it's easy to overdo the "slow squeeze" when you're engaged in slow fire bullseye shooting. You can get so intent on not letting the round go off unless the sight picture is perfect that you wait too long. Trigger control includes getting the round off in a reasonable time. Not too fast, but not too slow either.