Honoring the variation theory principle that meaning springs from differences, in this article we will show how two different strands of theorizing emerging from the mutual base of phenomenography have developed into developmental pedagogy and variation theory, respectively. Through looking at texts from these two strands, we will illustrate how they differ from (and are similar to) one another and argue that these differences can be explained through their different institutional embeddedness in preschool and school, respectively. The discussion will emphasize the important complementary contributions of both strands of theorizing.