RabbitMQ is a message broker that allows for asynchronous and reliable messaging. It supports features like guaranteed delivery, acknowledgments, and mirroring. Celery is a task queue library for Python that uses RabbitMQ. It allows for scheduling, monitoring, and retrying of asynchronous tasks. RabbitMQ and Celery can be used together to build distributed systems with low latency, fault tolerance, and resilience through acknowledgments, clustering, load balancing, and retry mechanisms.