Why does my internal storage take up so much space

A

AC Question

Hi, I recently noticed that I have +- 4GB of 6GB used space on my internal memory. I just bought a new memory card when I notice this when I moved all my data over to my sd card.. I also checked the hidden files but nothing of such so big.. Any help please

Ps. I have a Blu Life 8 with an usb port issue so I can't hook it up to my pc.. Also rooted with Kingroot