The following are the APIs that are used in this chapter.
PayPal is an Internet-based financial services company that provides payment and money transfer services through the Internet. PayPal also offers products for online merchants to accept payment over the Internet.
Website Payment Pro is a payment solution offered by PayPal that provides the capabilities of a merchant account and gateway. Website Payment Pro includes:
PayPal Direct Payment API, which enables a merchant to accept credit card payments directly on an e-commerce website
PayPal Express Checkout, which allows customers to pay using their PayPal account
Website Payment Pro is accessible through different means including the PayPal Name-Value Pair (NVP) APIs, the PayPal SOAP APIs and its various SDKs. In this chapter we will be using Website Payment Pro through its NVP APIs with the Ruby-PayPal library.