This document discusses big data and the Hadoop framework. It begins by defining big data as data that is too large to fit in a typical database or storage system. It then discusses how big data is generated in large volumes from various sources. The document introduces Hadoop as an open-source software framework for distributed storage and processing of large datasets across clusters of commodity hardware. It describes the key components of Hadoop, including the Hadoop Distributed File System (HDFS) for storage, and MapReduce as a programming model for processing and generating outputs from large datasets in a distributed manner.