Region
Regions are divided based on geographical location and network latency. Public services such as elastic computing, SFS, VPC network, elastic WAN IP, and mirrors are shared within the same Region.
Availability Zone
AZ (Availability Zone) refers to the physical area in which the power and network are independent of each other within the same region. An AZ is a collection of one or more physical data centers with independent cooling, fire extinguishing, moisture-proof, and electricity facilities. The distance between AZs is within 100 km. Multiple AZs in a region are connected using high-speed optical fibers to meet users' demands to build high-availability systems across AZs.
For more information about regions and AZs, and how to select them, see Region and Availability Zone.