Apache Hadoop has emerged as the storage and processing platform of choice for Big Data. In this tutorial, I will give an overview of Apache Hadoop and its ecosystem, with specific use cases. I will explain the MapReduce programming framework in detail, and outline how it interacts with Hadoop Distributed File System (HDFS). While Hadoop is written in Java, MapReduce applications can be written using a variety of languages using a framework called Hadoop Streaming. I will give several examples of MapReduce applications using Hadoop Streaming.