How to create a link to a directory [closed]

Symbolic or soft link (files or directories, more flexible and self documenting)

#     Source                             Link
ln -s /home/jake/doc/test/2000/something /home/jake/xxx

Hard link (files only, less flexible and not self documenting)

#   Source                             Link
ln /home/jake/doc/test/2000/something /home/jake/xxx

More information: man ln

/home/jake/xxx is like a new directory. To avoid "is not a directory: No such file or directory" error, as @trlkly comment, use relative path in the target, that is, using the example:

1. cd /home/jake/
2. ln -s /home/jake/doc/test/2000/something xxx

you should use :

ln -s /home/jake/doc/test/2000/something xxx