Apache Kafka is an event streaming platform that provides scalable, fault-tolerant, and reliable data processing capabilities. It captures events into event streams, which record the history of what has happened in the world as a sequence of events. These streams can represent hundreds of years of history and are ordered, allowing for causality to be inferred between events. In contrast, tables represent the state of the world at a particular point in time, typically "now," and are views of event streams that are continuously updated. The stream-table duality is a fundamental concept in event streaming, where a table is fully defined by its underlying change stream, and both streams and tables can be easily converted into each other. This duality enables continuous, streaming updates to both the stream and the table, allowing for real-time processing and analysis of data.