Payment Applications

PayPal

PayPal allows any business or consumer with an email address to securely, conveniently and cost-effectively send and receive payments online. PayPal is an e-commerce business allowing payments and money transfers to be made through the Internet. PayPal serves as an electronic alternative to traditional paper methods such as cheques and money orders. A PayPal account can be funded with an electronic debit from a bank account or by a credit card. The recipient of a PayPal transfer can either request a check from PayPal, establish their own PayPal deposit account or request a transfer to their bank account. PayPal is an example of a payment intermediary service that facilitates worldwide e-commerce.
Official Link 

Google Checkout

Google Checkout is an online payment processing service provided by Google aimed at simplifying the process of paying for online purchases. Users store their credit or debit card and shipping information in their Google Account, so that they can purchase at participating stores at the click of a button. Google Checkout also offers fraud protection, as well a unified page for tracking purchases and their status.
Official Link
Sumber : Daniel Adams