This document provides an overview of Cloudera's Distribution for Hadoop (CDH). It explains that CDH is a Hadoop distribution that packages Apache Hadoop and its ecosystem components in an easy to install way, similar to how Linux distributions work. The document outlines what is included in CDH, such as Apache Hadoop, Pig, Hive, HBase and ZooKeeper. It also describes how to install CDH using repositories, tarballs or on Amazon EC2. Finally, it discusses CDH versions and support options available from Cloudera.