When you import accounts, jobs or item records, each of these records must have a unique number. If you attempt to import an account or item with a duplicate number, FirstEdge will either reject the number or update the record's unique information in your company file, depending upon your selection here. (How to handle duplicate records when importing)
For example, if Item #100 already exists in your company file and you select Update Existing Record here, the information about Item #100 in your company file will be changed to reflect the information that's in the imported file if that file also contains an Item # 100.
If you choose to reject duplicate records, information about the duplicate record will be rejected and placed in the Import Log report that is created at the time you import.