What takes up space on a Debian partition?

Question

Debian

I decided to get acquainted with Linux, namely, I set myself a second Debian 8.6 system with xfce graphics (it seems to be called that).
I allocated 32 gigabytes on the disk with Windows, and, in fact, put everything there (during installation, I told the installer to automatically distribute everything on this partition)
There were no problems with understanding and working, but at some point I didn’t install the next package He cursed at the lack of free space. Executing "df" showed that my system partition was completely occupied, although I didn’t download anything except 1.5 console programs, wine and AIMP, and I’m sure that I couldn’t occupy 32 gigabytes with something of my own.
I thought it was some kind of bug and rebooted the system.
after the reboot, the graphics cursed at the lack of space and refused to start. In principle, I am friends with the terminal, but in fact I can’t work, because there is no place at all.
I can attach screenshots (resolute measures) if necessary.
The question is: how do I find out what the problem is and what should I do with it then?

Answer 1

du -hsx /*
https://linux.die.net/man/1/du