What is the difference between Hadoop API and Streaming

Question

What is the difference when we run hadoop program with Streamer jar and when we run it with program's jar file?

Answer 1

Usually we have Map/Reduce pair written in java..a map which splits the dataset into independent chunks, and a reduce which combines the results to perform some useful analysis...Hadoop streaming is a utility which allows us to write Map/Reduce applications in any language(like Ruby/Python/Bash etc.) that is capable of working with STDIN(for input) and STDOUT(for output)!