Fault tolerance is the capability of a computer system, network, or application to continue operating properly even if one or more of its components fail. This is achieved through redundancy, error detection, and automatic recovery mechanisms that ensure minimal disruption to services. In cybersecurity, fault-tolerant systems are crucial because they help maintain security controls and data integrity during hardware malfunctions, software errors, or cyberattacks. By designing systems with fault tolerance, organizations can reduce downtime, prevent data loss, and ensure business continuity, all of which are essential for maintaining trust and compliance in digital environments.