Fault-tolerance refers to tolerance of errors and those who make mistakes, allowing errors to occur within a certain range, but not all errors are suitable for fault-tolerant and error-correcting mechanisms. The "error" in the fault-tolerant and error-correcting mechanism is not a general violation of law and discipline, but a non-subjective error in the practice of reform, innovation and exploration, and an error within the scope permitted by policies, laws and regulations.

Different fields have different meanings. For example, in computer communication, it refers to the methods and technologies that can ensure uninterrupted service when an error occurs during operation and the system is activated.