Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
PHP is a general-purpose scripting language used for web development.
Plesk is a web hosting and server data centre automation software with a control panel developed for Linux and Windows-based retail hosting service providers.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.