In simple words, MQTT broker is a kind of cloud for IoT devices. It allows you to combine many IoT devices, possibly geographically dispersed, into a single information system.
Some devices can publish, receive, or publish and receive information (topics) simultaneously.
For more information, see here.
Local installation:
One of the most popular MQTT brokers is Mosquitto. It can be deployed on a single board such as raspberry pi or Orange, a Windows machine, and even on a router with Openwrt firmware.
One of the most popular self-deployment guides on the web is Mosquitto located here.
Cloud brokers:
- Popular cloud-based MQTT broker in our community WQTT.ru.
- You can also use demo mode or on a long-term basis broker on this site.
Also instructions on how to quickly raise a simple MQTT broker with your own hands.