[felix@gemini tt]$ ln -s hosts test
[felix@gemini tt]$ ls -al
total 8
drwxr-xr-x 2 felix felix 31 May 13 13:38 .
drwx------ 20 felix felix 4096 May 13 11:14 ..
-rw-r--r-- 1 felix felix 203 May 13 13:38 hosts
lrwxrwxrwx 1 felix felix 5 May 13 13:38 test -> hosts
[felix@gemini tt]$
That test isn't a real file, but a 'link' to the actual hosts file that I made. Those links can point to anywhere/anything. If the source file goes away, you get a broken link to it.
[felix@gemini tt]$ rm hosts
[felix@gemini tt]$ cat test
cat: test: No such file or directory
[felix@gemini tt]$ ls -al
total 4
drwxr-xr-x 2 felix felix 18 May 13 13:39 .
drwx------ 20 felix felix 4096 May 13 11:14 ..
lrwxrwxrwx 1 felix felix 5 May 13 13:38 test -> hosts