Comparison of white, beige and brown adipocytes in regard to their localization in specific depots in human and mice. Their major functions and progenitor cells are depicted. Major changes occurring during adipose tissue remodeling in obesity are highlighted. PVAT, Perivascular adipose tissue; CD, Cluster of differentiation; PDGFRα: Platelet-derived growth factor receptor alpha; Pax7, Paired box 7; En-1, Engrailed-1; Myf5, Myogenic factor 5;Ucp-1, Uncoupling protein-1; AT, Adipose tissue.