**Regions**: Geographical area on the planet with at minimum one but potentially multiple datacenters nearby and networked together with low-latency networks. **Availability zones** are physically separate datacenters within an Azure region. Each availability zone is made up of one or more datacenters equipped with independent power, cooling, and networking. **Region Pairs:** Most Azure regions are paired with another region within the same geography (such as US, Europe, or Asia) at least 300 miles away. This approach allows for the replication of resources across a geography that helps reduce the likelihood of interruptions because of events such as natural disasters, civil unrest, power outages, or physical network outages that affect an entire region. **Sovereign regions** are instances of Azure that are isolated from the main instance of Azure. You may need to use a sovereign region for compliance or legal purposes.