This document provides an overview of Apache Flink's streaming API. It first defines streaming data and common examples. It then discusses typical streaming data architectures involving data sources, collection, ingestion, processing, storage and visualization. The document also summarizes Flink's high-level design and components. Finally, it outlines the typical workflow for a Flink DataStream, including creating an execution environment, adding a source, creating a DataStream, partitioning, defining windows, applying business logic, and sending results to a sink.