Apache Kafka is a distributed event streaming platform designed for high-throughput, fault-tolerant, and scalable data pipelines. Originally developed by LinkedIn and now an Apache project, Kafka enables real-time data movement between systems through a publish-subscribe model built on append-only logs. Its ability to handle massive message volumes while maintaining durability and ordering makes it foundational for microservices architectures, data lakes, and stream processing applications. Understanding Kafka's architecture — topics, partitions, brokers, producers, and consumers — unlocks the ability to build systems that react to data in real time rather than batch-process it hours later.