Synchronization is the coordination of events to operate a system in unison. The familiar conductor of an orchestra serves to keep the orchestra in time.
Systems operating with all their parts in synchrony are said to be synchronous or in sync.
Some systems may be only approximately synchronized, or plesiochronous. For some applications relative offsets between events need to be determined, for others only the order of the event is important.
Today, synchronization can occur on a global basis due to GPS-enabled timekeeping systems.
Read more about Synchronization: Transport, Communication, Uses