Kafka is a distributed, fault-tolerant and highly scalable streaming platform that allow you to build real-time systems that can process millions of messages per second without data loss.
Kafka Connect is a data integration framework for connecting external systems, such as databases, message brokers, Hadoop platforms to an Apache Kafka cluster. Many connectors already exist and are available in open-source.
Kafka Streams is a development library for building complex data flow processing applications, similar to other solutions such as Spark or Flink. Kafka Streams makes easy and accelerates the implementation of microservices architectures based on Apache Kafka.