One of the most essential commands in Linux is the change directory command or
cd command. This is how you will navigate to different directories throughout your system. Using this command will change your current working directory to a different one you specify.
NTP stands for Network Time Protocol and is used for clock synchronization across multiple computers. An NTP server is responsible for keeping a set of computers in sync with each other. There are NTPD servers available over the internet to which you can sync, or you can run your own NTPD server and configure client computers to sync their times to it.
The SSH protocol in Linux is used to manage remote systems. Ordinarily, this would be another Linux system, but it could also be a firewall, router, or even a different operating system entirely. Using the SSH protocol to remotely log into another system will give you a command line terminal that you can fully access as if you were physically in front of the machine.
The purpose of this tutorial is to change the hardware clock in Linux. You may have wondered how your Linux system always has the correct date and time when you start up your computer, even if it does not have internet access. How is the computer keeping track of time even when it is powered off?
The nohup command in Linux is used to tell a process to ignore any
SIGHUP (hangup) signals that it receives. The SIGHUP signal is sent to a background job whenever the current terminal is closed. Thus, we can have a job in the background, close the terminal, and still see it running in the background.