COMPUTER FUNDAMENTALS

Detailed explanation-1: -Users specify a map function that processes a key/value pair to generate a set of intermediate key/value pairs, and a reduce function that merges all intermediate values associated with the same intermediate key.

Detailed explanation-2: -Mapper maps input key-value pairs to a set of intermediate key-value pairs. Maps are the individual tasks that transform input records into intermediate records.

Detailed explanation-3: -The mapreduce function automatically creates a KeyValueStore object during execution and uses it to store key-value pairs added by the map and reduce functions.

Detailed explanation-4: -Mapper produces the intermediate key values pairs and these are read by reducer. Data corresponding to same key is grouped together and after some processing final output will be produced in the form of key value pairs.