The technology used for online payment processing includes payment gateways, which facilitate transactions between customers and merchants. These gateways securely transmit payment information for authorization, ensuring that customers' financial data remains protected. Technologies like SSL (Secure Sockets Layer) encrypt the data exchanged during these transactions to prevent fraud. Key players in online payment processing include platforms like PayPal, Stripe, and Square, allowing businesses to accept various payment methods, including credit cards, debit cards, and digital wallets, making financial transactions more convenient.