If you’re new to Linux, and you want more even information than all the above helpful hints, this might also help:
P.S. If you would have read the above before installing gufw, you would have known that this is the Gnome Universal FireWall, whereas you’re on KDE and only need ufw as the KDE front-end to ufw can just be installed in KDE’s Control Panel System Settings.
P.P.S. This is a small mistake: leave things as they are as you’ve only lost a few MB of disk space and if it bothers you in a few months, ask a new question on how to replace gufw with ufw clearly mentioning you’re running KDE.
