Failure (fail, phail or flop) in general refers to the state or condition of not meeting a desirable or intended objective. It may be viewed as the opposite of success. Product failure ranges from failure to sell the product to fracture of the product, in the worst cases leading to personal injury, the province of forensic engineering.
The criteria for failure are heavily dependent on context of use, and may be relative to a particular observer or belief system. A situation considered to be a failure by one might be considered a success by another, particularly in cases of direct competition or a zero-sum game. As well, the degree of success or failure in a situation may be differently viewed by distinct observers or participants, such that a situation that one considers to be a failure, another might consider to be a success, a qualified success or a neutral situation.