Fault Masking is:

Fault masking occurs when one error or fault in a system effectively hides another error or fault. This means that the visibility of a problem is obscured by the presence of another issue, making it difficult to identify and diagnose the original fault. For instance, if a software application has two bugs, and the impact of one bug prevents the manifestation of the other bug, the first bug is said to mask the second. This scenario complicates debugging and can lead to a false sense of security regarding the software’s reliability, as the hidden faults are not detected, allowing them to persist in the system.

By understanding fault masking, testers can better appreciate the importance of thorough and varied testing strategies. This concept highlights the necessity of considering how different faults might interact within a system and the potential implications for software quality and reliability, as the presence of faults can significantly impact the testing process and the end-user experience.