Couchbase ensures high availability and disaster recovery through a homogeneous cluster architecture, replication, backup and restore, and rack zone awareness, allowing any node in the cluster to perform read and write operations, thus facilitating horizontal scalability. The blog outlines the process of creating a Couchbase cluster using the Couchbase Command Line Interface (CLI), which involves provisioning Couchbase nodes, initializing a "master" node, creating and adding "worker" nodes to the cluster, and rebalancing the cluster to distribute data evenly. These steps can alternatively be performed using the Couchbase REST API or the Couchbase Web Console. The cluster's homogenous nature means that it is not based on a master/slave architecture, which mitigates scalability issues and allows any node to function as the "master" if needed. The CLI commands are demonstrated for deploying on Amazon Web Services, where users can add and rebalance nodes to ensure the cluster meets growing application demands, with further resources provided for additional guidance and support.