A crash (or system crash) in computing is when a computer program (such as a software application or an operating system) stops functioning properly. Often it will exit the affected program after encountering this type of error. The program responsible may appear to freeze until a  crash reporting service reports the crash and potentially any details relating to it. If the program is a critical part of the operating system, the entire computer may crash, often resulting in a kernel panic or fatal system error, or in rare cases, an unstable network.