This document provides an overview of Apache Hadoop, including its architecture, components, and applications. Hadoop is an open-source framework for distributed storage and processing of large datasets. It uses Hadoop Distributed File System (HDFS) for storage and MapReduce for processing. HDFS stores data across clusters of nodes and replicates files for fault tolerance. MapReduce allows parallel processing of large datasets using a map and reduce workflow. The document also discusses Hadoop interfaces, Oracle connectors, and resources for further information.