This document discusses Apache NiFi and stream processing. It provides an overview of NiFi's key concepts of managing data flow, data provenance, and securing data. NiFi allows users to visually build data flows with drag and drop processors. It offers features such as guaranteed delivery, data buffering, prioritized queuing, and data provenance. NiFi is based on Flow-Based Programming and is used to reliably transfer data between systems, enrich and prepare data, and deliver data to analytic platforms.