1 - Paypal Web Payments Pro - this is a payment gateway that hides the paypal logo from view. It is the same as Authorize.net from a 'how it works' perspective.
2 - Express Checkout - this is the enhanced checkout system by paypal that has them go from our cart to their system and bypasses the entire one page checkout. it has pro's and con's. Configuration requires us to have an api user id, api password, and key.
3 - Standard Checkout - this is the most basic system and is free to use (except the trans fee that paypal charges) and all you need to configure it is your paypal email
