Zones, also known as availability zones, are physically separated locations within a CSP's region. By providing separate zones, CSP's can mitigate failures at any one zone within a region. Failures can result from issues with software and hardware, but also from natural events such as floods or fires. Some regions may have only one zone, but larger regions can have five or more regions to support their customers.

Circle size is relative to the number of zones in the region. A larger circle represents more zones.