This chapter delves into the physical design flow of IC, tracing the evolution of EDA tools from manual design to advanced automation. It covers the key steps in the design flow, including design entry, RTL synthesis, functional verification, floorplanning, placement, clock tree synthesis, routing, and physical verification. The chapter also compares commercial and open-source EDA tools, highlighting the advantages of open-source tools in terms of cost, flexibility, and community-driven innovation.