Although the wear-layer is what provides the bulk of the protection, vinyl flooring is always coated with a surface finish as well. The quality of this finish provides that first line of defense for your floors, before wear-and-tear start affecting the wear-layer itself. There are many different finishes on the market with a range of names, but the standard you want to demand is “ceramic bead coating”. This is essentially a urethane coating, but with microscopic beads of ceramic product that provide an additional layer of protection (and anti-slip properties). These beads are invisible, and do not affect indoor air quality, but are a nice additional benefit to look for.