Apache Kafka is an open-source distributed event streaming platform used by thousands of companies for high-performance data pipelines, streaming analytics, data integration, and mission-critical applications.

Kafka combines three key capabilities so you can implement your use cases for event streaming end-to-end with a single battle-tested solution:

To publish (write) and subscribe to (read) streams of events, including continuous import/export of your data from other systems.
To store streams of events durably and reliably for as long as you want.
To process streams of events as they occur or retrospectively.
And all this functionality is provided in a distributed, highly scalable, elastic, fault-tolerant, and secure manner.
Kafka is a distributed system consisting of servers and clients that communicate via a high-performance TCP network protocol.