This document provides an overview of Hortonworks DataFlow (HDF) 3.1 and its new and enhanced features. Key highlights include improved ease of use through integration with Atlas, SmartSense and Knox, enhanced flow management capabilities with Apache NiFi Registry for version control and migration of flows, and improved operational efficiency through features like test mode in Streaming Analytics Manager and group-based policy support in Ranger. The document also discusses use cases for data ingestion, stream processing, and enterprise data movement between data centers and cloud.