Difference between Error, Defect and Failure in software testing ?

Error: The mistakes made by programmer is knowns as an ‘Error’.  This could happen because of the following reasons:

-           Because of some confusion in understanding the functionality of the software

-           Because of some miscalculation of the values

-           Because of misinterpretation of any value, etc.

Defect: The bugs introduced by programmer inside the code are known as a defect. This can happen because of some programatical mistakes.

Failure: If under certain circumstances these defects get executed by the tester during the testing then it results into the failure which is known as software failure.