Time code: Location recording   

On location time code is used in many different ways. 
If the camera generates time code 
then the recorder will record that signal in addition to the audio. This makes synchronization of sound rolls with picture a very simple process. 
If the camera doesn't generate time code 
than a slate is required to find the various takes. If an electronic slate is used (one where time code is dislayed in a large LED display) then it is fed code from the recorder and the camera films the slate at the start of the take. This gives the exact information as to where the audio is to be found on the picture itself. 
Video shoots may use a master clock to sync both camera and recorder.