Yes and no.
It fires a “pattern” of shot. How big this pattern is and if it will hit something depends on two things, the “Choke” of the shot gun, and the type of shot.
A choke is the last 3-4" inches of the barrel where the barrel gets a bit narrower. There are differences in how narrow, and modern shot guns often allow one to adjust it by screwing in custom choke tubes.
So with a cylinder choke will have a 40" pattern at 25 yards, where as a full choke will have a 40" pattern at 40 yards.
Next, the type of shot will have some effect on what you hit. Shot for like birds or skeet shooting are tiny little pellets maybe .09" diameter. They have different sizes with the higher the number the smaller the pellet. So skeet or quail should be a 7 or 8. Something larger like a duck might be a 5.
For home defense or bigger critters, one would use buck shot. It comes in different sizes, with the common 00 Buckshot being .32" in diameter. Using buck shot for birds or a trap shooting is a fools errand because with a 40" spread you only have 9 pellets, vs with no 8 shot you have ~400 pellets.
To make things even more confusing, many shot guns can also fire slugs - which are just very large bullets. Those can be used to hit things accurately under 100 yards with ease. In short with the right choke, the shot gun is the most versatile gun out there. If I had to pick just one to survive off the land, it would be a shot gun. They are also very easy to reload for.
Yes, they are used in sport. Mostly for trap and skeet, which fling out clay pigeons. So it is a form of target shooting, but one with moving targets and one has to learn to properly swing and follow through. They are also used in 3 gun or tactical competition. I am not sure what kind of shot they use, bird shot or buck shot, but they are shooting at steel plates at fairly close ranges, so at 5 yards the pattern might be only 5" wide.
