Displays a tree of all sub-directories of the current directory to any level of recursion or depth. If used with /F switch, displays not only sub-directories but also files.

Show directory tree:

$ tree
Folder PATH listing for volume Windows
Volume serial number is 3207-BC63
C:.
├───apptranslator
│ ├───docs
│ ├───scripts
│ ├───static
... more output

Show directory tree, including files:

$ tree /f
Folder PATH listing for volume Windows
Volume serial number is 00000177 3207:BC63
C:.
│   out.txt
│   t.cpp
│   
├───apptranslator
│   │   .gitignore
│   │   .pylintrc
... more output

Links:

$ tree /?
Graphically displays the folder structure of a drive or path.

TREE [drive:][path] [/F] [/A]

   /F   Display the names of the files in each folder.
   /A   Use ASCII instead of extended characters.