Shipping, Orders, And Taxes
Displaying products and letting people transfer money electronically is a totally different thing and requires extra setup. Payment Gateway’s checks to make sure that funds are available. If funds aren't available the Payment Gateway will return that information to the website. Many gateways give you the option to authorize or to authorize and capture. Authorizing mean you verify that you can make the charge if you want. If someone enters an incorrect credit card number it will be caught at this step. Paypal, very basic you can't have a cart, you can't manage orders, you can't automatically deliver files, and you can't create site-wide sales. PayPal is a good example of an off site gateway. Any time you are accepting credit cards on your site, make sure you have an SSL Certificate.