This document provides an overview of building an ETL pipeline with Apache Beam on Google Cloud Dataflow. It introduces key Beam concepts like PCollections, PTransforms, and windowing. It explains how Beam can be used for both batch and streaming ETL workflows on bounded and unbounded data. The document also discusses how Cloud Dataflow is a fully managed Apache Beam runner that integrates with other Google Cloud services and provides reliable, auto-scaled processing. Sample architecture diagrams demonstrate how Cloud Dataflow fits into data analytics platforms.