Fault : It is a condition that causes the software to fail to perform its required function.
Error : Refers to difference between Actual Output and Expected output.
Failure : It is the inability of a system or component to perform required function according to its specification.
- Failure: External behavior is incorrect
- Fault: Discrepancy in code that causes a failure.
- Error: Human mistake that caused fault
- Error is terminology of Developer.
- Bug is terminology of Tester