What are error records in BDC? | ABAP BDC

Records already existing in the database table are called as Error Records. Such Error Records can be handled efficiently using CALL TRANSACTION statement. The error records from the flat file can be handled using this method. Whenever SAP comes across error records, these are displayed in a user-defined screen. CALL TRANSACTION <tcode> statement is used to call the user-defined screen to populate the error records.