In ICAI material it writes, Under Stratification: when performing test of details the population is often stratified by monetary value. This allows greater audit effort to be directed to the larger value items. Under Value- Weighted: when performing test of details it may be efficient to identify the sampling unit as individual monetary units that make up the population. One benefit of this approach to defining the sampling unit is that audit effort is directed to the larger value items. The last lines of both. They seem same. Please explain to me what is the main difference (crux) between these two sample design techniques?