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.
Tidio is a customer communication product. It provides multi-channel support so users can communicate with customers on the go. Live chat, messenger, or email are all supported.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.