Key points

• Availability zones are separate datacenter groups within one Azure region.
• Zone-resilient architecture requires supported services, capacity, routing, and state to span the intended zones.

Best-known use cases

• Keep a regional workload operating after the loss of one datacenter zone.

What candidates often confuse it with

• Zones protect against an in-region fault; a multi-region design addresses loss of the entire region.

Key takeaway

Use availability zones when the service and all critical dependencies must survive a zone failure without leaving the region.

Relevant exam tasks

• D3.2.S1 — Recommend a high availability solution for compute
• D3.2.S2 — Recommend a high availability solution for relational data

Learn more

• Virtual machine reliability