Updated: Jan 18
In the Azure cloud, resources are created in dedicated regions, which are different geographical locations around the globe that contain Azure datacenters. Microsoft had built a lot of data centers for Azure, where each datacenter's site is called Region, and there are ~60 Azure regions across the globe (more than any other cloud provider).
Almost every new resource in the cloud should be allocated to a region. When you create a new virtual machine, you will be requested to specify the Region to host it. Also, when you use a service, you are using physical equipment in one or more of these locations.
You can find the updated list of Azure datacenters here:
As you can see, Azure is spread across all the world, and you can find Azure regions across all continents. This fact is important as these regions give you the flexibility to bring applications and services closer to your paying customers no matter where they are. Also, Global regions provide confidence as they provide scalability, preserve data residency for your services, and redundancy when needed.
It is also essential to understand that each data center is called Zone when discussing regions. Some of the regions have more than one physical data center; the Region is said to have "Availability Zones," which is incredible as it ensures that your services and data are redundant (in case of massive failure in one of the datacenters) and that your clients can still be able to use your product. Azure provides services (See here) that benefit from the use of availability zones and can skip from one Zone to another without affecting the customer service.
Availability zones are created using one or more datacenters, meaning that some regions have designated pair regions. This is done for increased availability when a whole region fails - the other one can fill its space. One last thing to know is that pairing regions can only be set by Azure and cannot be changed by the user.
Each Azure Region is always paired with another region within the same geography (such as Europe, Asia, etc.) at least a few hundred miles away, which ensures that at least one Region will be operative in case of failures (e.g., natural disasters, network outages, etc.)
Here is a list of a few of the Microsoft Azure Region Pairs: