Fault tolerance is a concept in computer science and engineering that refers to the ability of a system to continue operating properly in the event of hardware or software failures. Fault tolerance techniques are used to ensure reliable and continuous operation of systems, even when components fail. This can involve redundancy, error detection and correction, and other strategies to mitigate the effects of faults and failures. Fault tolerance is crucial in critical systems such as aerospace, healthcare, and financial industries where system failure can have serious consequences.