Explain Azure Availability Zones vs Availability Sets.

Availability Zones are physically separate datacenters within an Azure region, each with independent power, cooling, and networking. Deploying resources across zones protects against datacenter-level failures and provides 99.99% SLA for VMs. Availability Sets are a logical grouping within a single datacenter that ensures VMs are distributed across fault domains (separate physical racks) and update domains (separate maintenance windows), protecting against hardware failures and planned maintenance. Use Availability Zones for highest resilience; use Availability Sets when zone support is unavailable or for legacy workloads.