Both of these are vintage (old-school) silver-tip hollow-point brass-cased defense rounds probably circa late 1980s to early 1990s. The 10mm Auto is on the left while the 9x19mm is on the right. Both are made by Winchester. Aside from just a size comparison, if you look at the headstamps, you will see that (because it was necked down from .30 Remington), 10mm uses a rifle primer while 9mm uses a small pistol primer.