NATS is a server for streaming data. It can be used as a pub/sub service like Redis, but it also implements RAFT consensus so that it can be used for globally-ordered, durable streams (more like Kafka). The server itself is a lightweight Go binary and it's much nicer to manage than alternatives.

NATS is a message broker. It uses TCP or websocket, support "core" messaging aka simple fire and forget messaging, request/response, pub/sub. And then message queues, subscriptions, topics, consumers, memory and replay functionality. Also a MQTT compatible protocol.

I felt the same but had more luck. I found this comparison in their docs[1]: 'NATS Comparison to Kafka, Rabbit, gRPC, and others'.

1: https://docs.nats.io/nats-concepts/overview/compare-nats

I didn't stop looking and followed link to the version announcement, then went to the front page of nats.io from the top left of that page.

And I also still have absolutely no fucking idea what any of this is.