Voucher Approval in Tally used to Authorize vouchers before reflects the books of accounts. Admin can Set levels & rights based on Amount & type of transaction.
Transaction authorization is a module where the effect of the transaction appears in the books of accounts only when it is authenticated by the authorized person. Many companies maintain a system of approval where the data operator only creates the entry and sends for approval to higher department where the actual verification and authentication of the transaction takes place this work flow process of authorization is maintained through authorization module.