Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
PHP is a general-purpose scripting language used for web development.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.