A RabbitMQ message broker facilitates communication between components by creating queues for producers to exchange messages with consumers. RabbitMQ simplifies development processes, such as task queues, event-driven architectures, micro-services communication, distributed systems, and IoT messaging. It provides a reliable and scalable way for these communications, ensuring no noticeable delay in response. The tutorial demonstrates how to decouple a part of a Laravel application into a worker using RabbitMQ, allowing for efficient communication between the worker and the parent application.