MQTT, or Message Queuing Telemetry Transport, is a lightweight and scalable messaging protocol designed for efficient communication between remote devices with limited network bandwidth and small code footprint. It uses a publish-subscribe messaging transport model and has become the de facto standard for IoT and M2M communication due to its reliability and efficiency. MQTT is an open OASIS standard and an ISO recommendation, widely adopted and well-supported by various software and hardware vendors. Its components include clients and brokers, which implement the publish/subscribe model through their interactions. MQTT is used in various applications such as smart metering, ambient sensor data, machine health data, and billing systems, with implementations existing from companies like HiveMQ, Thingstream, Mosquitto, AWS IoT, and Azure IoT. Twilio also supports MQTT through its IoT offerings, providing two device builder platforms for different audiences, including Twilio Microvisor and Twilio Electric Imp.