>What

In Emacs: Press Ctrl + x, Ctrl + f and type the path of the file to open on a remote host:

/ssh:user@host:filename

>Why

You can edit files directly on other hosts using a locally installed Emacs. The remote host does not need an editor installed, it just needs an SSH server.

This can be practical for editing files on embedded hosts.

>Reference

From the man pages:

>>gnu emacs:Remote-Files

You can refer to files on other machines using a special file name syntax:

/method:host:filename
/method:user@host:filename
/method:user@host#port:filename