Sales Transaction is the custom entity shipped along with the solution. This entity is where all the Accounting history i.e. Quote, Order, Invoice, Credit Memos, Sales Receipt and Accounting Balance i.e. Current balance, Total balance, Last transaction date, Year to Date sales, Aging details and Inventory updates of any record is stored in this entity when synced from QuickBooks to Dynamics 365 CRM. The purpose of developing this custom entity is to provide the same look and feel of the record when synced. As there is no same architecture of Dynamics 365 CRM and QuickBooks.