PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.
PHP is a general-purpose scripting language used for web development.
PrestaShop is a freemium, open-source ecommerce solution, written in the PHP programming language with support for the MySQL database management system.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.