map stageInput for map stage is a <key value> pair and it produces the <key,value> pair as the output.
Shuffle stage All intermediate values which are associated with the same intermediate key, are grouped together and given as an input to the reduce stage.
Reduce stageAll intermediate values belongs to the same intermediate keys, are processed and a new set of key value pair is generated as output and it is stored in the HDFS.
Research breakthrough possible @S-Logix
