HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
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.
W3 Total Cache (W3TC) improves the SEO and increases website performance and reducing load times by leveraging features like content delivery network (CDN) integration and the latest best practices.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.
WPBakery is a drag and drop visual page builder plugin for WordPress.