Pulling the trigger is the motion the operator performs to discharge a firearm. Although very simple in principle, it produces problems for many shooters, even experienced ones.
Let me give you the fundamentals first:
1. Hold the gun firmly with your proper grip
2. Align the sights on the target
3. Place the center of the first pad of your trigger finger on the trigger
4. Begin pressing the trigger rearward, smoothly, without moving anything else (or as little as possible).
5. Once you have created enough pressure on the trigger, it will move until the striker, firing pin or hammer in the gun is activated and starts the ignition process, firing the gun.
Numerous things happen in the gun to cause it to fire. The part you control is pulling the trigger. If done properly, nothing moves, not your hands or the sight picture and the pistol fires a round specifically where you intended. Even so, if you “twitch” or “wince” before or at the moment you fire the gun, the shot will most likely head someplace other than where intended. In my experience, a excellent trigger pull is just one of, if not the most important part of shooting effectively. Serious shooters spend many, many hours refining their trigger pulling. Top marksmen can pull the trigger so well they never move the gun out of alignment. New shooters have a habit to pull the trigger in a snappy manner that can move the gun quickly out of alignment and cause the shot to miss.
I’ve included a video to help demonstrate some key ways to hold and fire a gun.