React is a JS library that is used to build user interfaces. It is mostly used in making single-page and mobile applications.
Webhook is a very friendly and helpful way to get notified when something happens. In a web application, when something happens or an event occurs a message is posted via URL. Sometimes, you only need data when something happens, otherwise, you don't require any data. In conventional ways, a web application keeps fetching data from the database rather than waiting for any event that overwhelms the server by compromising more resources. Webhooks gives relaxation to the server and notifies when some event happens.