Apache Kafka is an open-source platform designed for building real-time data pipelines and streaming applications. It enables high-throughput, low-latency processing of data streams, allowing for real-time data ingestion, storage, and processing. Kafka is used to handle large volumes of data across distributed systems and is popular for its scalability and fault tolerance. It integrates with various data systems and tools, providing a unified solution for managing and analyzing data in real-time.