This document discusses a Hadoop Job Runner UI Tool that was developed to provide a graphical user interface for running Hadoop jobs. The tool allows users to browse input data locally, copy the data to HDFS, copy Java classes to remote servers, run Hadoop jobs, and copy results back from HDFS to display outputs and job statistics. The document also provides background on Hadoop and MapReduce, including an overview of how MapReduce works and how it enables distributed and parallel processing of large datasets.