A kernel panic is a safety measure taken by an operating system's kernel upon detecting an internal fatal error in which either it is unable to safely recover or continuing to run the system would have a higher risk of major data loss. The term is largely specific to Unix and Unix-like systems. The equivalent on Microsoft Windows operating systems is a stop error, often called a "blue screen of death".

The blue screen of death is a critical error screen displayed by the Microsoft Windows and ReactOS operating systems in the event of a fatal system error. It indicates a system crash, in which the operating system has reached a critical condition where it can no longer operate safely.