There may be times where logging into a computer remotely is necessary. You may require access to a file, need to assist a friend with a problem, or even transfer files between computers. Whatever it is Secure Shell (SSH) lets you connect to another computer running Linux (or indeed another Unix system like BSD or Solaris) over an encrypted connection. For a remote host to receive SSH connections, it must have the daemon running (sshd) and you must have it accept incoming packets to port 22 if a firewall is used.