Azure Region: When creating a resource in Azure, you must choose a region, which is a specific geographic area containing one or more data centers. A dedicated, low-latency network connects these data centers. Some Azure services are only available in particular regions. Selecting the region closest to the resource users is essential to keep business-critical data nearby.
Availability Zone: An Availability Zone comprises one or more physically separated data centers within the same region, connected by a high-speed network. Each data center within an Availability Zone has its own independent power, cooling, and networking systems. Based on your requirements, you can replicate data across different data centers. This ensures that if one data center goes down, you can still retrieve data from another.