When exporting your song, loop or FX in FL Studio, you get to choose what to do with the "tail" of your rendered audio.
Here is a quick explanation of each of these tail settings:
renders the song while keeping any decaying sounds at the end of the song. This is the go-to setting when you are exporting a song, since you usually want to keep the decaying sounds at the end of your song (reverb, delay and so on).
to use when you want to create loopable loops. Wrap Remainder will render the tail of the selection, that is any decaying sound: including the reverb, delay and the part of the instrument that keeps playing after the last bar (release). It starts rendering the last bar, and puts the decaying sounds at the beginning of the loop. Important note about loops: always use the .wav format, since .mp3 inserts a short silence before the loop.
The setting to use when you want to cut the exported sound at the last bar, selection or time marker. No reverb tail or delay is exported, which may result in the exported sound's volume being cut abruptly.
Fun story about why I started to search for this:
As I had to export perfectly loopable loops for a video game project, I encountered an issue: when exporting from the FL Studio mixer directly ("arm track" and then "render to wave files"), the end of each loop was cut off. As a result, my loops were not looping smoothly, even if I tried to tweak the "tail" settings.
The only solution was to use the regular export menu ("File --> Export"). Hope this will help someone :)
Do you have any question about FL Studio? Feel free to leave a comment below and I will do my best to answer you in a next blog article!
Source: FL Studio 20 Reference Manual