In shortApache Kafka is a distributed event streaming platform that durably writes events to partitioned topics and delivers them to several consumers.
In Kafka, producers append events to the partitions of a topic and consumer groups read those records at their own pace. Because records are kept for a set time, a new consumer can also re-read past events.
It differs from MQTT in being designed more for central data platforms and high-volume event processing; MQTT is more common for messaging close to the field and Kafka for enterprise stream processing. They are also used together.
In OPC Router projects
With the Apache Kafka plug-in OPC Router can carry production events to an event streaming platform.