Explanation/Reference:
Explanation:
Note 1: External Unique ID. Refers to the external ID of the current record to be imported. The External Unique ID is directly involved in duplicate checking.
If no External IDs exist or you don't map External IDs in your file to the External ID fields in the application, the application determines duplicates by comparing certain fields Note 2: Your CSV file might have External IDs, which are generated by many software systems. Using External IDs makes importing from external systems easier, where a primary key/foreign key relationship is represented by storing IDs in the related file. If you have External ID codes for each of your records, you can use the Import Assistant to update fields in those records (except the External ID field). If you do not have External ID codes, you can only update those fields that are not used for duplicate checking.