Availability zones are separate and distinct areas within a region, and each availability zone (AZ) has its own data center. AWS’s us-east-1 region, for example, has six availability zones. (This is actually AWS’s largest region; three AZs per region is the most common pattern). AZs are designed to be isolated from one another so that if one availability zone experiences an outage, applications and data can fail over to another availability zone in the same region.