In terms of video or audio, sychronisation reffers to the coordination of separate feeds so that everything plays back at the same time. It is extremely important in our industry and a good example of audio and video out of sync is lip sync. We’ve all seen bad examples of this when we hear words before seeing lips move on screen!
In professional AV, a Time Code or SMPTE code is often used to achive a perfect sync. As the name suggests,the system uses the same format as the 24 hour clock with the addition of frames after seconds. For our needs, which are primaraley playback of video and audio, a sync is essentail when multiple clips need to be played back together.