Ubuntu is the linux distribution we use, more specifically the kubuntu implementation to support kde.
To check which release you have:
lsb_release -a
This returns something like:
laussy@wulfrun2:~$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 19.10 Release: 19.10 Codename: eoan
Should that fail you can also find it in:
cat /etc/issue
Available online here: https://packages.ubuntu.com/