Kubuntu is a derivative of the Ubuntu Linux distribution. Uses the KDE desktop environment instead of GNOME. In fact, these are the main differences between these systems. The distribution is part of the Ubuntu project and uses its basics. You can install both the KDE desktop environment (kubuntu-desktop package) and the GNOME desktop environment (ubuntu-desktop package). 
        The operating system is updated every six months along with Ubuntu. At the moment Kubuntu is being developed only by the community. Support is planned until the beginning of 2023