MQTT is a lightweight messaging protocol designed for efficient communication with IoT devices that prioritize low power consumption and minimal bandwidth usage. It is particularly useful in applications like agriculture, industrial automation, and transportation, enabling real-time monitoring and control while conserving resources. Unlike the HTTP protocol, which operates on a request/response model, MQTT uses a publish/subscribe model that facilitates asynchronous message delivery, making it ideal for environments with limited data transmission capabilities. This protocol can be implemented in various programming languages through MQTT client libraries, and it operates through an MQTT broker to handle message exchange. Popular MQTT brokers include Eclipse Mosquitto, EMQX, HiveMQ, and VerneMQ, with cloud-based solutions from AWS, Microsoft Azure, and Google Cloud also supporting MQTT for IoT device data management. MQTT's architecture ensures efficient and reliable communication across large-scale deployments, and its simplicity and low overhead make it a popular choice for both IoT and real-time communication applications, such as Facebook Messenger. The protocol functions over TCP/IP and uses a topic-based system to filter and route messages effectively.