What service is a fully managed real-time messaging service that allows you to send and...

Google Cloud Pub/Sub is a scalable, durable event ingestion and delivery system.

-> Pub/Sub allows services to communicate asynchronously, with latencies on the order of 100 milliseconds.

-> Pub/Sub is used for streaming analytics and data integration pipelines to ingest and distribute data. It is equally effective as messaging-oriented middleware for service integration or as a queue to parallelize tasks.

-> Pub/Sub enables you to create systems of event producers and consumers, called publishers and subscribers. Publishers communicate with subscribers asynchronously by broadcasting events, rather than by synchronous remote procedure calls (RPCs).

Reference link- https://cloud.google.com/pubsub/docs/overview