Fault-tolerant systems are designed to continue operating properly even when one or more components fail. These systems use redundancy, meaning they have backup components or processes that can take over if something goes wrong. This ensures that the overall system remains functional and reliable, minimizing downtime and preventing data loss. Common examples of fault-tolerant systems include data centers, aircraft control systems, and financial transaction systems. By implementing techniques such as error detection, data replication, and automatic recovery, these systems can maintain performance and safety, making them essential in critical applications where reliability is paramount.