What are Failure and Faults?

Failure 

Failure is something dynamic. The program has to be executed for a failure to occur. The term failure relates to the behavior of the program, This is the very general definition of failure. It can include such things as deficiency in performance attributes and excessive response time.

Fault 

A Fault is the defect in the program that when executed under particular conditions causes a failure. There can be different sets of conditions that cause failure or the conditions can be repeated. Hence a fault can be the source of more than one failure. A fault is a property of the program rather than a property of its execution or behavior.