Ablative lasers and non-ablative lasers are two different categories of laser treatments used in cosmetic dermatology, primarily for skin resurfacing and rejuvenation. The distinction lies in how they affect the skin and their level of invasiveness. Ablative lasers remove the outer layer of skin (epidermis) and can also penetrate into the deeper layers (dermis). Non-ablative lasers do not remove any skin layers. Instead, they heat the underlying layers of skin without damaging the surface.