still not enough storage...

i have no less than 5 pics, I backed up my phone to icloud and still no enough storage. even the music on my phone is less than 10 songs. And also apps. i don't have facebook, insta, google, or even pinterest, but somehow, my storage is almost full. Even deleted all my cache from safari, and web pages and i still have not enough space. Saved all my photos and videos on my laptop, and only cleared some MB. It's anoying, because even if I"ve already tried to do something about it, my storage shows that most of GB are filled with "other"... What "other"? what is this? besides the sistem that filled 5,43GB, "OTHER" filled 7,31 GB!