text: **Important:**All path parameters and commands are*case-sensitive*. 
  
  Sometimes when you choose a directory, such as /usr/lpp/ars/V9R5M0/bin, you see a 
  different path when you run**pwd**because a symbolic link is set. A*symbolic link*is a file that 
  contains the path name for another file or directory. Only the original path name is the real 
  name. An*external link*is a type of symbolic link; it links to an object outside of the 
  hierarchical file system (HFS). Typically, it contains the name of an IBM MVS™ dataset. 