Rosacea has two components that show up differently on the skin, and each is treated separately.
Inflammation
Papules, pustules, and flare frequency come from an inflammatory response in the skin. This component is managed with prescription topicals or oral therapy, which reduce how often flares occur and how severe they are.
Dilated blood vessels
Persistent background redness comes from small blood vessels dilating near the skin surface. Because this is a change in the vessels rather than in the inflammatory response, it is treated with vascular lasers. Pulsed dye and KTP wavelengths are absorbed by hemoglobin inside the vessel, which heats and closes it while limiting the effect on surrounding tissue. The body clears the treated vessel over the weeks that follow, and the redness lightens. Treatment is delivered as a series, with the number of sessions and the interval between them determined by the device used, how extensive the visible vessels are, skin type, and how the skin responds to earlier sessions.
Most patients present with both components, which is why the two categories are frequently used together rather than as alternatives.