This interface is called the command line; you type in a command and it
  displays the result. The shell we are using is called the korn shell (ksh).
  
  If you come from the Linux world, it's similar to bash, but simpler.
  
  Finally, display the file README. But this time, we are not going to use
  cat, but instead less:
  
  $ less README
  
  (Again, don't type the $ dollar symbol; the $ dollar symbol means: run as
  normal user)