What kind of devices support MQTT?

MQTT is designed for low power and low bandwidth devices hence called lightweight messaging protocol. It could be used in any devices, usually small, embedded devices. MQTT works on a publisher-subscriber model that makes forwarding data to multiple subscribers easy. 

You can read more information on how to connect MQTT to favoriot platform here:  https://platform.favoriot.com/tutorial/?javascript#mqtt

https://cedalo.com/blog/mqtt-connection-beginners-guide/. The article is not overcomplicated, and you will be able to understand it even if you are not an IT professional and just want to know what MQTT is, what it’s used for, and what MQTT brokers and clients are. "}" data-sheets-userformat="{"2":513,"3":{"1":0},"12":0}">MQTT devices are basically anything that can connect to an MQTT broker and host an MQTT library. MQTT connection is implemented in many industries - automotive, manufacturing, smart home, and many others.
If you want to know more about this protocol, I recommend reading this simple article about it: https://cedalo.com/blog/mqtt-connection-beginners-guide/. The article is not overcomplicated, and you will be able to understand it even if you are not an IT professional and just want to know what MQTT is, what it’s used for, and what MQTT brokers and clients are.