Answer
Output VAT is the VAT a business charges on its sales (owed to the tax authority). Input VAT is the VAT a business pays on its purchases and expenses (reclaimable from the authority). The VAT return reports both, and the business pays or reclaims the net difference.
Output VAT (on sales) - Input VAT (on purchases) = VAT payable/(reclaimable).Real-world example The VAT account collects output VAT as a credit and input VAT as a debit; the balance is what's owed.