Requests to GCP first pass through edge **Points of Presence** (POPs). From the POP, the request is routed to either a data center or an Edge Node (collectively referred to as Google Global Cache (GGC); you may also see Edge Nodes referred to as Content Delivery Network (CDN)). There are many more Edge Nodes than POPs, so Edge nodes can be used to cache commonly referenced information for a particular region. GCP is connected to the rest of the internet via peering, which (in this context) means an agreement between Google and an Internet Service Provider (ISP). ## regions and zones Google Cloud is divided into regions. Regions are subdivided into zones. Zones can be composed of multiple data centers, but often a zone is a single data center. Connectivity with zones is very fast, typically requiring less than 5ms for a round trip signal. Zones can be a single failure domain, so you might spread an application across multiple zones. For applications with broad customer bases, applications can be spread across multiple regions. Regions are guaranteed to be at least 160 km apart and so unlikely to be effected by the same disaster.