Database clustering is a technique used to improve the performance and availability of databases. It involves grouping multiple database servers, or nodes, to work together as a single system. This setup allows for load balancing, where requests are distributed among the nodes, enhancing response times and reducing the risk of downtime. In a clustered database environment, if one node fails, the others can continue to operate, ensuring data remains accessible. This redundancy is crucial for applications that require high availability. Popular database management systems, such as MySQL and PostgreSQL, offer clustering features to help organizations manage their data more effectively.