You can check the release of Raspbian, simply reading the content of the os-release file.
cat /etc/os-releaseHold down both Alt+PrintScreen, and while holding those keys, hit the following keys in sequence, one at a time, with a few seconds pause between them:
R E I S U B
A handy mnemonic to remember that is, Reboot Even If System Utterly Broken.
Substitute O for B to shutdown the system instead of rebooting (O=off, B=boot).