What is the Pro DJ Link function? And what link functions are there?

PRO DJ LINK offers various link functions that can be used by connecting a Pioneer DJ player (CDJ-2000nexus, CDJ-2000 or CDJ-900) or DJ mixer (DJM-2000 or DJM-900nexus) supporting the PRO DJ LINK function or a computer on which rekordbox (Mac/Windows) is installed by LAN cable. The main link functions that can be used with this unit are shown below.

1. Music files on various devices (smartphones, tablets, computers, USB devices, SD memory cards, etc.) can be shared and played on up to four DJ players.
2. The “Beat Sync” function lets you automatically synchronize the tempos and beat positions of tracks on up to four DJ players for playback.
3. The “Traffic Light” function lets you easily find tracks that have a good affinity with the key of the track currently playing on any linked player.
4. The “Status Information” function lets you immediately grasp the DJ mixer’s channel status (on air status and channel number).
5. The “Quantize” function lets you hold performances keeping the loops and hot cues of DJ players and the beat effects of DJ mixers in beat with the track.