The WhatsApp Business API, now also called the WhatsApp Business Platform, is Meta's interface that lets software send and receive WhatsApp messages on a business number instead of a person typing on a phone. There is no app to open; the number is connected to a system such as an ordering platform or a chat tool, which can run an automated bot, let several staff answer from one number, send approved template messages to thousands of customers, and apply for the verified badge. Meta charges for business-initiated messages, while replies to customers inside the 24-hour service window are free.
Why it matters
The free WhatsApp Business app works for a home baker taking ten orders a day. The moment orders need to be captured as structured data, printed in the kitchen, paid online and tracked by more than one person, the app runs out. The API is what makes an ordering bot possible: the customer picks items, the system builds the cart, takes payment and confirms, with nobody at the counter typing. It is also the only way to message more than 256 people at once or to message people who have not saved your number. The comparison in WhatsApp Business vs WhatsApp Business API explains which one a given restaurant needs.
Example
A tiffin service with 300 subscribers wants to send tomorrow's menu every evening and take skip requests. On the app, that is two broadcast lists that reach only the people who saved the number, and a person reading replies till midnight. On the API, one template goes to all 300 at Meta's utility or marketing rate, which in India is well under a rupee per message, so the evening send costs a few hundred rupees at most, and the skip replies land in a dashboard where the kitchen reads a single count. The API pricing explainer walks through what Meta charges.
Tezzu runs on the WhatsApp Business API and sets up the connection for you through Meta's embedded signup; you keep your own number and the setup takes about 30 minutes.