The WhatsApp Business Webhooks API are user defined HTTP callbacks that are triggered by specific events. WhatsApp will see the event, collect the data, and send a notification to the Webhook URL. When a customers message is received, WhatsApp Business will send an HTTP POST request notification to the Webhook URL. This includes notifications for; Inbound Message, Inbound Media Message, Inbound Replies to Sent Messages and more. The WhatsApp Business API provides a way for businesses to interact with and reach customers globally to connect with them on WhatsApp using end-to-end encryption. This enables messages and calls with security that allows only you and the person you're communicating with to read or listen. WhatsApp Messenger is an SMS replacement application.