Hadoop job configuration
<p>Could someone explain me what's the use of configuration in the case of hadoop ?</p>

<p>And also explain me the following code:</p>

<pre><code>// Create a new JobConf
JobConf job = new JobConf(new Configuration(), MyJob.class);

// Specify various job-specific parameters     
job.setJobName("myjob");

FileInputFormat.setInputPaths(job, new Path("in"));
FileOutputFormat.setOutputPath(job, new Path("out"));

job.setMapperClass(MyJob.MyMapper.class);
job.setCombinerClass(MyJob.MyReducer.class);
job.setReducerClass(MyJob.MyReducer.class);

job.setInputFormat(SequenceFileInputFormat.class);
job.setOutputFormat(SequenceFileOutputFormat.class);
</code></pre>