Data items (in dataports)

Yes if the record is inserted automatically; otherwise, No. The default value is Yes.

If AutoSave is set to No, then imported records are not automatically inserted into the appropriate tables. To insert records manually, use the OnAfterImportRecord Trigger. For example, use the OnAfterImportRecord Trigger if you need to evaluate the records before inserting them, or if you want to calculate or retrieve additional data before inserting the record.

If a record already exists and AutoSave is set to Yes, the value of the AutoReplace Property determines whether the imported record overwrites the existing record.

Reference