Толковый словарь английского языка - differentiation

noun Date: 1802 the act or process of differentiating, development from the one to the many, the simple to the complex, or the homogeneous to the heterogeneous, 3. modification of body parts for performance of particular functions, the sum of the processes whereby apparently indifferent or unspecialized cells, tissues, and structures attain their adult form and function, the processes by which various rock types are produced from a common magma