To add further to the excellent (and quite correct) info that mingaa gave you:
2-3/4 Dram Eq = measurement of powder when black powder was used as a propellant.
Serves as a guide to how much velocity and recoil there will be.
The higher the number the more powder and more kick and speed.
To put your load in perspective, 12-ga shells in the 2-3/4" length have shot payloads usually found from 1-oz thru 1-1/8 oz to a max of 1-1/4 oz (usually). Of course, the more shot weight the more pellets are in the cloud of shot for the same size pellets, which is called a shot column. It doesn't add to the effective range, but helps ensure a better or more likely hit on target. So your 1-1/8 oz payload is a "medium weight" regarding the total pellet count.
Using Remington STS/Premier advertised data (Federal is almost identical but I'm most familiar with Remington), you'll see that 12-ga 2-3/4" shells come in different velocities for target and hunting.
Remington 12-ga 1-1/8 oz Target load velicities vary based on Dram Weight, including
1100-fps
1145-fps
1200-fps
1235-fps
and their Nitro Sporting Clays 1-1/8 oz loads go
1300-fps
1350-fps
And their hunting loads are quite similar but use different wads to arrive at different shot patterns (shape of the cloud) than what target (trap, skeet, clays) wads pattern for shooting.
So all that is just to help illustrate that your box of ammo is a medium payload, with fairly light recoil and a slower velocity compared to other 12-ga 1-1/8 oz ammo available. These shells are typically found used by the majority of shooters because they are easy on the gun, easy on the shooter and quite effective as target or dove loads where you might shoot hundreds in an outing.
Sorry so long, but I hope it helped somewhat.
