Most common Desktop printers or photo copiers cannot print to the edge of a piece of paper & the same applies to a sheet of labels.
Its usually around 5mm from each edge of the sheet of paper
If you are having problems with your print lining up with your labels, sometimes this is a good indicator of the problem, if you look at the next image (below) you will see that the print area isn’t central and the print is coming out much more to the bottom of the sheet. This can be caused by the printer slipping when pulling the sheet in to print.
Other problems can be caused by the feed rollers not putting the sheet in equally giving you a wonky print. The image below shows a sheet that has been printed slightly wonky. If you take a look you can see that the top tight corner is closer to the edge of the paper then the top left. And similarly the bottom right is further away from the edge then the bottom left.
If your sheets are coming out like this you may need to adjust your image to compensate for it. You can do this be rotating the image by a fraction of a degree in the opposite direction. Alternatively you may need to fix, replace or repair your printer feed roller to fully correct this problem. But in most cases you should be able to adjust the print image to correct most cases.