There is an NTP Server just a time server that uses the protocol NTP. NTP is undoubtedly the most widely used although other time protocols do exist. The terms ‘NTP server’, ‘time server’ and ‘network time server’ are interchangeable and frequently the terms ‘radio clock’ or ‘GPS time server’ are utilized but these merely describe the procedure that the time servers are given a time reference.
Atomic clocks work with the principle that the single atom (in most cases the caesium -133) will resonate at an exact speed at certain energy levels. The correctness of atomic clocks is indeed adept that UTC was created to permit international Atomic Time (TAI) and Greenwich Meantime (GMT) to be blended, allowing for the slowing of the Earth’s rotation by the addition of leap seconds and thus keeping the Sun at the Earth’s meridian at noon. Failure to account for this particular slowing would lead to the eventual drift (albeit in many millennia).
The protocol was developed to provide exact synchronization of time between NTP Server and clients. Internet established NTP servers synchronize their time to exact external reference clocks, for example GPS, national radio time standards or precise atomic clocks. Accurate time is passed from the NTP server to network clients.
A time signal will be received by a committed NTP server . The web is possibly the most usual sources of UTC time (Coordinated Universal Time), yet, as a timing source can be a cause for several time server difficulties utilizing the net. Firstly Internet time sources can’t be authenticated; authentication ensures that a timing reference is coming from where it says it is and is the in built security measure of NTP.
On the same note to use an Internet timing source would mean that a gap would need to be created in the network firewall, this can clearly cause its own security issues. Internet time sources can also be notoriously incorrect. A survey by MIT (Massachusetts Institute of Technology) found less than a quarter of Internet time sources were any where near exact and often those that were, were too far to provide a reliable timing source.