Conversations in WhatsApp Business API refer to interactions between a business and a user or customer that last 24 hours. This 24-hour window begins when the business sends a message to a user or when the business responds to a message from a user.
All messages exchanged between the business and the user within these 24 hours are considered part of the same conversation. This means that businesses can send and receive multiple messages within this period without initiating a new conversation.