Clustering is a technique used in DevOps to parse large datasets quickly, giving IT teams more time to work on other projects and improving flexibility, cost-efficiency, and reliability in applications. Clustering allows for scalability through vertical scaling and horizontal scaling strategies, amplifying availability for applications. It enables data to be stored together based on its hash slot, improving performance and scalability. The technique is used by companies like Uber and Amazon ElastiCache to achieve high availability and maximize application performance. To get started with clustering, developers can follow along with hands-on demos and take advantage of supplemental tutorials and Redis cluster specification links.