WhatsApp API's Overview

Why WhatsApp API? WhatsApp API offers User-initiated & Business-initiated:

User-initiated functions for a conversation that initiates in response to a user message. Whenever a business replies to a user within the 24-hour customer service window, that message will be associated with a user-initiated conversation. In addition, companies can send free-form messages within this 24-hour customer service window.

Business-initiated for a conversation that starts from a business sending a user a message outside the 24-hour customer service window. Messages that initiate a business-initiated conversation will require a message template.