The architecture of the data center physical layer is based on logical hardware pods and the physical network topology. Figure 1. Physical Infrastructure Design Pod ArchitectureThe VMware Validated Design for SDDC uses a small set of common building blocks called pods. Pod TypesThe SDDC differentiates between different types of pods including management pod, compute pod, edge pod, shared edge and compute pod, and storage pod. Each design includes several pods. Physical Network ArchitectureThe physical network architecture is tightly coupled with the pod-and-core architecture, and uses a Layer 3 leaf-and-spine network instead of the more traditional 3-tier data center design. Availability Zones and RegionsIn an SDDC, availability zones are collections of infrastructure components. Regions support disaster recovery solutions and allow you to place workloads closer to your customers. Typically multiple availability zones form a single region.