MapReduce is the heart of Apache® Hadoop®. MapReduce is a programming paradigm that runs in the background of Hadoop to provide scalability and easy data-processing solutions. In general terms, MapReduce is a framework for embarrassingly parallel computations that use potentially large data sets and a large number of nodes. Ideally, it also uses data that is stored locally on a particular node where the job is being executed. The computations are embarrassingly parallel because there is no communication between them. The run independent of one another.