In Rekordbox what is Track Analysis?

TRACK ANALYSIS

Normal: Suitable for analysis of tracks which have a
relatively consistent.

Dynamic: Suitable for analysis of tracks which contain
significant tempo changes.

Normal analyzing doesn’t change yours BPM while playing track.
Dynamic analyzing can change yours BPM. That means If you playing song that started with house 128 bpm if is there in the middle of the song part of hip hop 100 BPM you will see this change. If you are using sync your second deck 2 will be cloned as deck 1 same BPM.

ANALYSIS PROCESS

The difference between PERFORMANCE and NORMAL Concurrent Analysis Process Mode is the number of tracks analyzed at one time.

Performance: Will analyze as many files as your CPU can handle.

Normal: Is a bit more conservative usually only requiring about half the CPU usage.