Which files in mobile phone storage can be deleted?

These three folders are system files and cannot be deleted.

These folders are not only in the mobile phone storage, but if your phone has been cracked,

then in the C drive (mobile phone storage), D drive (system ROM) and E drive These folders can be seen in (memory card).

The reason why you see that the SYS folder is 0KB may be that your phone does not have cracking permission.

It is not recommended that you delete these files. If the memory space is not enough, you should change a memory card or delete some songs, videos, etc.

The reason why the mobile phone storage space is small, It may be because you have some large files such as songs, photos, videos, etc. stored here. For example, files transmitted via Bluetooth may still be stored in the mobile phone storage. Another reason is that a lot of software is installed in the mobile phone storage. Yes, it may be caused by having installed a lot of software before and then uninstalled it, but there are still some files that have not been uninstalled cleanly.