Retinol and retinal are both retinoids, forms of vitamin A crucial for skincare. Retinol requires an enzyme to convert to retinal, which then binds to skin receptors, exerting beneficial effects. In contrast, retinal can directly bind to receptors, bypassing the enzyme requirement. Both stimulate collagen production, reduce wrinkles, and improve acne, but retinal is more potent and may cause less irritation due to its direct conversion to the active form. The choice between retinol and retinal depends on factors such as skin sensitivity and desired results.