An infused pre-roll is a regular pre-roll with concentrate added to the flower. Common add-ins include distillate, live resin, rosin, kief, hash or THCA diamonds. Some are rolled in kief on the outside, and some have concentrate mixed through the ground flower or drizzled inside.
The point is a stronger, sometimes more flavorful smoke. An infused pre-roll can easily carry a much higher total THC than a standard pre-roll, so it can hit harder and faster than you expect. If you are new or have a low tolerance, take a puff or two, put it out, and wait several minutes before deciding whether you want more. You can relight it later.
Always check the label to see what was added and the total THC. "Infused" can mean very different things: a light dusting of kief is not the same as a gram of flower loaded with live resin. The ingredient list and the COA will tell you the details.
Infused pre-rolls can burn a bit slower and unevenly because the concentrate melts. Light the tip evenly and rotate as you go. Store them in their tube away from heat so the concentrate does not melt into the paper.