Explain the concept of fault tolerance in software safety. How can redundancy and error detection techniques be employed to achieve fault tolerance?

Fault tolerance is a critical concept in software safety, especially in systems where safety and reliability are paramount, such as aviation, healthcare, automotive, and industrial control systems. It refers to a system's ability to continue functioning correctly in the presence of faults or failures, whether they are caused by hardware errors, software bugs, environmental factors, or malicious attacks. The goal is to ensure that the software system remains safe, reliable, and operational, even when problems occur.