what's the difference between "hadoop fs" shell commands and "hdfs dfs" shell commands?

Are they supposed to be equal?

but, why the "hadoop fs" commands show the hdfs files while the "hdfs dfs" commands show the local files?

here is the hadoop version information:

Hadoop 2.0.0-mr1-cdh4.2.1 Subversion git://ubuntu-slave07.jenkins.cloudera.com/var/lib/jenkins/workspace/CDH4.2.1-Packaging-MR1/build/cdh4/mr1/2.0.0-mr1-cdh4.2.1/source -r Compiled by jenkins on Mon Apr 22 10:48:26 PDT 2013