# Publish / Subscribe — Redis

Source: https://www.geekswithgeeks.com/en/redis/redis-pubsub-basics

> Broadcast messages to any client listening in real time.

## Channels, not keys

Pub/Sub is separate from the key-value store. Clients **subscribe** to named channels; any client that **publishes** to that channel fans the message out to all of them instantly.

## Subscribing

Open a terminal and subscribe — this client blocks, waiting for messages on the channel.

```bash
redis-cli SUBSCRIBE notifications
```

Output:

```
1) "subscribe"
2) "notifications"
3) (integer) 1
```

## Publishing

From a second terminal, publish a message — the subscriber above receives it immediately.

```bash
redis-cli PUBLISH notifications "New order #4521"
```

Output:

```
(integer) 1
```