Google Cloud Pub/Sub is a messaging service that allows applications to communicate with each other in real-time. It enables the exchange of messages between independent systems, making it easier to build scalable and reliable applications. With Pub/Sub, messages are sent to a central hub and can be processed by multiple subscribers, ensuring that data is delivered efficiently. This service is designed to handle large volumes of messages and can automatically scale to meet demand. It supports various programming languages and integrates well with other Google Cloud services, making it a versatile choice for developers looking to implement event-driven architectures.