The extent to which a software performs its intended functions without failures, is termed as ______.

Explanation

Reliability is defined as the probability of failure-free operation of a software product for a specified time in a specified environment, i.e. the extent to which it performs its intended function without failing. Robustness is different — it measures how gracefully the software copes with unexpected or invalid inputs and abnormal conditions. Correctness is the degree to which the software satisfies its specification, a static conformance property rather than a failure-rate property. Accuracy refers to the precision of the computed results. Because the question stresses operation "without failures", the answer is reliability.