This document discusses the evolution from traditional RDBMS to big data analytics. As data volumes grow rapidly, traditional RDBMS struggle to store and process large amounts of data. Hadoop provides a framework to store and process big data across commodity hardware. Key components of Hadoop include HDFS for distributed storage, MapReduce for distributed processing, Hive for SQL-like queries, and Sqoop for transferring data between Hadoop and relational databases. The document also outlines some applications and limitations of Hadoop.