Differentiation has become an indispensable teaching approach to meet the needs of diverse learners, and has thus garnered a lot of attention, particularly on a theoretical level. This has resulted in an abundance of differentiation models and frameworks. Despite the attention given to differentiation, most teachers still seem to struggle with implementing it in practice. The previous models have therefore failed to provide teachers with a clear and easy-to-use framework for differentiation. For this reason, we have created the 5-dimensional (5D) model of differentiation which aims to be a more accessible and tangible model than the existing ones. The model approaches differentiation through five dimensions, which are 1) "teaching arrangements," 2) "learning environment," 3) "teaching methods," 4) "support materials" and 5) "assessment." The model draws on "constructivism," "Zone of Proximal Development" (ZPD), "Theory of Multiple Intelligences" and "motivation" as its core theoretical underpinnings. The model stems from the Finnish educational context but can be transferred to and applied in various school contexts. In this article, we will first review various definitions of differentiation. We will then critically examine some of the existing models for differentiation. Finally, we will elaborate on the theoretical underpinnings and different dimensions of our 5D model.