Synchronization is the coordination of events to operate a

system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment (systems), environment, is described by its boundaries, ...

in unison. For example, the

conductor Conductor or conduction may refer to: Music * Conductor (music), a person who leads a musical ensemble, such as an orchestra. * ''Conductor'' (album), an album by indie rock band The Comas * Conduction, a type of structured free improvisation ...

of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are said to be synchronous or ''in sync''—and those that are not are '' asynchronous''. Today, time synchronization can occur between systems around the world through satellite navigation signals and other time and frequency transfer techniques.

Navigation and railways

Time-keeping and synchronization of clocks is a critical problem in long-distance ocean navigation. Before radio navigation and satellite-based navigation, navigators required accurate time in conjunction with astronomical observations to determine how far east or west their vessel traveled. The invention of an accurate marine chronometer revolutionized marine navigation. By the end of the 19th century, important ports provided time signals in the form of a signal gun, flag, or dropping time ball so that mariners could check and correct their chronometers for error. Synchronization was important in the operation of 19th-century railways, these being the first major means of transport fast enough for differences in

local mean time Local mean time (LMT) is a form of solar time that corrects the variations of Solar time#Apparent solar time, local apparent time, forming a uniform time scale at a specific longitude. This measurement of time was used for everyday use during the ...

between nearby towns to be noticeable. Each line handled the problem by synchronizing all its stations to headquarters as a standard railway time. In some territories, compa