What was the specialization labor for sumerian

Specialization of labor is when after the establishment of cities humans no longer needed to focus on multiple skills to survive because there was large amounts of people and there was enough people to do those skills such as hunting and farming. So there is basically a lot of free time for people to focus and hone one skill such as pottery. In Sumer there was multiple specialization in labor. People were able to specialize in pottery, metal working, sculpting, an much more. So this question is a little vague I hope I helped you understand it a little more.