AP Workflow is an electronic invoice tracking and authorization process that manages the uploading of invoice images, data entry, coding to general ledger accounts, and approval process to authorize final payment to suppliers. It integrates with ERP systems and includes features like workflow diagrams, generated emails, worklists, voucher details, images, cost allocation, approval routes, and notes. Key benefits are that invoices are approved, fewer invoices get lost, suppliers get paid on time to receive discounts, and it provides resource efficiency within the AP department.