Each user's home directory contains at least one sub-directory for his incoming email, one for his document files, one for temporary files and one for his executable files (programs). There will be others.
When you log in, UNIX automatically puts you in your home directory. You can create, edit or delete any file or sub-directories within your home directory or any of its sub-directories. But you cannot do so in anybody else's home directory without their permission.
| cd | transfers you to your home directory |
| cd mail | transfer you to your mail directory |
| cd .. | transfer to the parent of the current directory |
| pwd | displays the current working directory |
| mkdir source | make sub-directory called source in current directory |
| rmdir source | kill the source directory within current directory |
| ls | list contents of current directory |
| ls source | list the files in the source directory |
| ls .. | list the contents of the current directory's parent |
| mv dir1 dir2 | if dir2 does not exist, renames dir1 to dir2, but if it does, creates dir1 as a sub-directory of dir2 |