rekordbox
Track management software from AlphaTheta (Pioneer DJ). It handles analysis of tracks, making playlists, and saving hot cues, and the basic flow is to export to USB and load it on a CDJ. It can also be used by connecting to a computer and performing.
What rekordbox can do
In rekordbox you import tracks and analyze them to find their BPM, key, waveform, and beatgrid. Then you group tracks into playlists and prepare each track by setting hot cues and MEMORY CUEs.
The prepared tracks can be exported to a USB stick and used on CDJs, or you can connect a computer to a DJ controller and play from it directly.
The basic preparation flow
① Import the track files. ② Analyze them and check that the BPM and beatgrid are correct. Fix them if not. ③ Set hot cues or MEMORY CUEs where you want to bring the track in. ④ Group the tracks you will use into playlists. ⑤ Export to a USB stick.
If you skip ②, SYNC and QUANTIZE will line up to the wrong position on the night. Before exporting, check that the beatgrid sits on the beats.
How it differs from Serato DJ
Serato DJ is another piece of software for managing tracks and playing with them. Whichever you choose, the flow of preparing tracks and mixing them stays the same.
The difference shows up in which gear you pair it with. If you play from a USB stick on a club's CDJs, exporting from rekordbox is the basic flow. Home DJ controllers sometimes only work with specific software depending on the model, so check before you buy.