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