WhatsApp Business API differentiates between two types of communications:
Notifications & alerts (business-initiated conversation)
Companies can initiate a customer interaction with notifications like appointment reminders, shipping confirmations or delivery tracking information.
When you want to start communicating with an end user, you must set up message templates. When sending message templates, they can be personalized, translated and allow for minimal variable text through programmable variables. Every message template must be approved by WhatsApp before it can be used.
Media message templates in the form of images, PDFs, locations, videos and interactive buttons are also available as company-initiated conversations and go through a similar approval process as text-based message templates. Find more information about media message templates here.
Support Window (user-initiated conversation)
Each time an end user sends a message to a WhatsApp Business Account, the business has a 24 hour “support window” to reply to the end user with a message. Enterprises are free to personalize and design the communication without any approval needed or third party editing. Support windows are applicable for customer service, feedback, surveys, and more.