Regions and Zones

Regions are related to where groups of datacenters are physically located, for example UK West may be located in and around Bristol.

Regions may have more than one physical datacenter associated with then, each of these is known as a Zone.

Where there is more than one datacenter in a regon it is said to have Availability Zones.

Some cloud services can benefit from Availability Zones if one particular datacenter fails, the workload and traffic can be automatically transferred to another datacenter.

Paired Regions

Some regions have a designated paired region, so when a full region fails another can take its place. Some cloud services can make use of this. The pairings are defined by Microsoft, for example North Europe and West Europe.

Data is replicated between the paired regions.

Regions Selection Considerations

Almost every resource should be placed in a region.

When selecting a region you should consider:

Consideration	Description
Geographical proximity to the system's target audience	Pick a region as close to the users as possible.
Service availability	Not every service is available in every region. See this page for details.
Availability Zones	If you require the region to have more than one physical datacenter, in case of strict redundancy requirements.
Pricing	Some cloud service pricing varies between regions.