cd

Use cd to change directory. Use pwd to see what directory you are in.

   % cd english
  % pwd
  % /u/ma/jeremy/english
  % ls
novel poems
  % cd novel
  % pwd
  % /u/ma/jeremy/english/novel
  % ls
ch1 ch2 ch3 journal scrapbook
  % cd ..
  % pwd
  % /u/ma/jeremy/english
  % cd poems
  % cd
  % /u/ma/jeremy

Jeremy began in his home directory, then went to his english subdirectory. He listed this directory using ls, found that it contained two entries, both of which happen to be diretories. He cd'd to the diretory novel, and found that he had gotten only as far as chapter 3 in his writing. Then he used cd .. to jump back one level. If had wanted to jump back one level, then go to poems he could have said cd ../poems. Finally he used cd with no argument to jump back to his home directory.