What do you mean by Audit Sampling?

Application of audit procedures to less than 100% of the population of documents/ items relevant for audit such that all sampling units have a chance for selection (for applying audit procedure thereon) so as to provide the auditor a reasonable basis on which conclusion about the entire population can be drawn. However, the sample design, size & selection of items for testing should meet the following: Purpose of the audit procedure and population characteristics shall be considered for designing an audit sample. Sample size shall be so chosen as to reduce sampling risk to an acceptable low value. Random sampling, whenever practicable, shall be considered so that each sampling unit shall have reasonable chance of selection. For sampling, use of stratification and value-weighted selection will increase audit efficiency.