Authentic means genuine not a knock off. These are authentic and look exactly like the ones players wear but are for general public. Players are a lot fitter, slimmer than us so their jerseys are more fitted and more stretchable and don’t have any embroidery. Some replicas have embroidery either 3 stripes or club/country emblem.
So they are replica of actual players match jersey which usually retails for $120. But they are not knock off.