What is the role of a message broker in Celery and why is it necessary for the task system to work?

In Celery, the message broker acts as an intermediary between the client (the application that submits tasks) and the workers (processes that execute these tasks). It receives tasks from the client and distributes them to the workers.

Why is a broker necessary:

• Task Queue: The broker stores tasks in a queue, ensuring their reliable delivery.
• Asynchrony: It allows the client to not wait for the task to complete but simply to enqueue it.
• Scalability: The broker enables distributing tasks among multiple workers.

Commonly used brokers are RabbitMQ and Redis. Without a broker, Celery cannot efficiently manage tasks and their execution.