Availability Zones (AZs) are distinct locations within a cloud region that are engineered to be isolated from failures in other AZs. They offer physical redundancy and operational independence in terms of power, cooling, and networking to ensure high availability and fault tolerance for cloud services and applications. By distributing resources across multiple AZs within the same region, cloud service providers like Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP) enable their users to build resilient and scalable applications capable of withstanding outages or failures in any single location. This architectural approach allows for seamless failover mechanisms, minimizing the impact of incidents and ensuring continuous operation. The use of multiple AZs is a fundamental practice in cloud computing for achieving optimal uptime and maintaining robust data protection and disaster recovery strategies.