Increasingly, patients are requesting information and treatments to ameliorate the effects of skin aging. Skin aging is a biological process determinated by endogenous and exogenous factors. Cosmetic interventions may have a significant impact on the health and well-being of patients. Over the last years, several antiaging strategies have been developed, and doctors must be up to date with these constant advances. Interventions, for the facial aging mainly, may be categorized into four “Rs” of facial rejuvenation: resurfacing (chemical peels, dermabrasion, microneedling, and ablative and non-ablative lasers), redraping (the various pulling and lifting facial surgical procedures), relaxing (chemodenervation with paralytic agents), and replacement/recontouring (the use of filling agent for superficial and deep soft tissue augmentation). However, before delving into the techniques to perform cosmetic procedures, it is essential to have full knowledge of the histology, physiology, and topographic particularities of the skin. This first chapter is also the first and essential step for the construction of your knowledge on cosmetic procedures. So, make sure you understand every detail before you move forward.