In HPE there are around 100+ lines in a sales order, so the Order management team would want to check if all the lines in that particular sales order are having the required information. Hence, this entity V2 sales orders header and lines is being used by the order management teams in HPE which should be available in all D365 Versions.

In V3 sales order headers and V3 sales order lines we are getting individually the lines & header information for all sales orders, whereas, in V2 sales orders header and lines a single sales order information can be extracted with both header and line details per sales order.