MQTT is an ISO standard publish-subscribe-based messaging protocol. It works on top of the TCP/IP protocol. It is designed for connections with remote locations where a 'small code footprint' is required or the network bandwidth is limited.
The following are the things covered under MQTT.
What is MQTT and how does it work with WebSphere MQ?
How to setup MQTT and start testing
An Android Studio port of the Eclipse Paho Android Client Example
This enables it to be extremely efficient both on the wire, and in memory. It also makes it quick and easy to get started and to learn.
URIs are useful to provide serval pieces of information in a single compact string. They can be used to convey all the information required to connect to a MQTT server.
There are servers specific to MQTT support; many of these servers have much wider capabilities beyond just MQTT.
The following are the course contents offered for MQTT
Download MQTT course plan