Payment processors are third-party companies that facilitate online transactions by securely transferring funds between customers and merchants. They play a crucial role in ensuring that payments are processed quickly and securely, helping businesses to accept various forms of payment such as credit cards, debit cards, and digital wallets. Payment processors also help reduce the risk of fraud and chargebacks, making online transactions more reliable for both parties involved. Overall, payment processors are essential for enabling e-commerce businesses to efficiently manage their payment transactions.