Would you please explain what automatic file update does?

If I turn it off as recommended, what will I need to do manually? And when?

Thank you!

Automatic file update checks if all of the required bootstrap includes are in the head tags. As this happens on each save/close/open some users experience some slowdowns.

Thanks. When I have it turned on, it also tries to copy the bootstrap files into whatever folder the file I'm opening is in. When I have it turned off, it does not do this. Is that intentional? I may not be stating exactly accurately what I saw.