The PHP code in the “After Row” area is executed after the record in the current Excel file row has been saved into the Database.
Usually, in this area, you can set all the fields that don’t have a corresponding column in the import file, because they are calculated starting from other fields’ value.
Another use case is when you need to update the array of objects created in the “Before Run” area used to verify the uniqueness of a record. After an insert, you should add the new record to the original data collection / array created when the import starts.