tramp-mode is great for editing files remotely, but sometimes having a shell and Emacs together on the same file can be invaluable.
eshell opens up a shell which is like a regular Unix shell, but is written completely in Elisp, so it's built-in to Emacs and is completely portable.
eshell has many interesting properties, but let's focus on editing files remotely.
eshell, it is possible to change the working directory into a remote directory with the same syntax as
tramp-mode. Yes, no manual ssh-ing to the remote machine, it's more like a fuse-sshfs connection, but without fuse and without the manual mounting!
Changing to a remote directory is trivial:
~ $ cd /ssh:email@example.com: /ssh:firstname.lastname@example.org:/root $
From there, you can continue to use the shell, but you can also start to edit any file with
C-x C-f or
Apart from that it feels pretty much like a mount point to which you can copy files from and to and so forth.