differentiation
dif.fer.en.ti.a.tion \-.ren-che--'a--sh*n\ n 1: the act or process of differentiating 2: development from the one to the many, the simple to the complex, or the homogeneous to the heterogeneous 3a: modification of body parts for performance of particular functions 3b: the sum of the processes whereby apparently indifferent cells, tissues, and structures attain their adult form and function