This document provides an introduction to big data, including what it is, sources of big data, and how it is used. It discusses key concepts like volume, velocity, variety, and veracity of big data. It also describes the Hadoop ecosystem for distributed storage and processing of large datasets, including components like HDFS, MapReduce, Hive, HBase and ecosystem players like Cloudera and Hortonworks. The document outlines common big data use cases and how organizations are deploying Hadoop solutions in both on-premise and cloud environments.