This is a feature that allows you to record midi in free time and then tap a beat with your controller to the free time notes which then aligns the notes fairly closely to the beat marks. It would create a tempo map at the same time it realigns the beats without altering the feel of the original track. The beats are realigned to the music.
This will give you rhythm accuracy and most importantly the ability to quantize your free time recorded tracks for creating accurate notation.
This is a feature found in some DAWs. Some also do this with imported audio but just the midi feature would be nice.