NTP

NTP: Network Time Protocol, keeping clocks synchronized on machines connected to a network

in the IT world machines need to have ​accurate time across the network for a lot of reasons.  ​There are some security service like Kerberos, and network authentication ​protocol that depend on the time being consistent across the network to work

You can’t depend on the hardware itself to keep consistent time, ​so you might want to set up an NTP server. ​There are different ways that an IT support specialist or ​sysadmin can do this for an organization. ​You can use a local NTP server or a public NTP server. ​

To set up a local NTP server, ​you can install NTP server software on your managed server. ​Then, you install NTP clients on your machines and ​tell those computers which NTP servers to sync their time to. ​This is a great option, ​because you can then manage the entire process from end to end.

Public NTP servers are managed by other organizations that your client machines ​connect to in order to get synchronized time. ​This is an awesome way to utilize NTP without having to run a dedicated NTP ​server. ​But if you have a large fleet of thousands of machines, ​it’s a better etiquette to be running your own NTP service. ​

Another good practice is to run your own NTP server, ​then have that point to a public NTP server. ​This makes it so that you don’t connect all your clients to a public NTP server, ​and you don’t have to measure time synchronization.