Explain tolerable error under ISA 530?

A monetary amount set by the auditor in respect of which the auditor seeks to obtain an appropriate level of assurance that the monetary amount set by the auditor is not exceeded by the actual misstatement in the population. 

Tolerable error : -Audit evidence gave rise to confirming amendments to ISA 530 *In obtaining audit evidence; the auditor should use professional judgment to assess the risk of material misstatements and design further audit procedures to ensure this risk is reduced to an acceptably low level. *When designing audit procedures; the auditor should determine appreciate means for selecting item for testing so as to gather sufficient appropriate audit evidence to meet the objectives of the audit procedures