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Webhooks provide a way for a web application to notify another application about the events occurring in the former application. For example, when a user signs up for a new account on any service, the web application may send a notification to an external application to handle user registration. A webhook is a lightweight version of APIs or a reverse API as it is an event-based one-way form of communication between two web applications. API is a set of rules that govern how two applications communicate with each other, which is typically used when two applications need to share resources.