OpenNTPD.

OpenSSH is a computer program. This program is used in order to have encrypted communications over the internet. It encrypts the information so others can't read it.

The -X flag to the OpenSSH client enables X11 forwarding. The server must also have support for forwarding enabled.

Source: ssh(1) manpage

~/.ssh/known_hosts

An SSH server is a daemon that listens for requests to log in using SSH from remote computers. SSH basically allows you to control a Linux or Unix computer just as if you were sitting at the physical machine.