This document provides an introduction to Big Data and Apache Hadoop. It defines Big Data as large and complex datasets that are difficult to process using traditional database tools. It describes how Hadoop uses MapReduce and HDFS to provide scalable storage and parallel processing of Big Data. It provides examples of companies using Hadoop to analyze exabytes of data and common Hadoop use cases like log analysis. Finally, it summarizes some popular Hadoop ecosystem projects like Hive, Pig, and Zookeeper that provide SQL-like querying, data flows, and coordination.