Final answer:
The Mapper Output (intermediate key-value data) is stored in the local disk of each individual mapper node during the MapReduce process.
Step-by-step explanation:
In the MapReduce programming model, the Mapper Output (intermediate key-value data) is stored in the local disk of each individual mapper node. During the Map phase, the mapper processes the input data and generates the intermediate key-value pairs. These pairs are temporarily stored in the memory buffer of the mapper and are periodically written to the local disk. Once the Map phase is completed, the intermediate data is ready for the Shuffle and Sort phase, where it will be transferred and consolidated to the reducer nodes for further processing.