What is copy files to iTunes music folder when adding library?

The "copy file to iTunes music folder when adding library" option in the iTunes music player enables users to create a local redundant backup of all the music files that they add to their iTunes library. This feature enhances data security and ensures the availability of music files in case the original files (referenced by iTunes), get deleted or damaged. By selecting this option, you can rest assured that your entire iTunes music collection is safely stored on your local drive.