During the course of audit, auditor is not able to obtain “absolute” assurance due to ” Inherent limitations” of audit. Hence the auditor is required to obtain “reasonable” assurance to form an opinion as its objective as specified under SA 200.
absolute assurance = 100% assurance
not possible in audit
because of inherent limitations = drawback of audit process (like limited time and power)
hence absolute assurance = high level of confidence (more than 80-90%)
this was very simple concept if you are facing problem in this you should take proper guidance