A corrected return on Form 8288 is a submission of previously reported withholding tax information that has been amended due to errors or omissions. It is filed to correct any inaccuracies in the original return. The corrected return should be filed as soon as possible to minimize any potential penalties or interest charges. An original return, on the other hand, is the initial submission of withholding tax information for a given tax year. It should be filed accurately and timely to ensure compliance with U.S. tax laws and regulations.