From what I have been able to piece together, the firewall that comes with Ubuntu is iptables, which is very complicated, so an easier way to access the firewall is through UFW and GUFW. UFW is accessed through commands, and GUFW is a graphical interface that makes configuring the firewall easier than UFW. Is this accurate?
Also, what types of rules should be defined under the firewall? Are the default settings enough under a fairly secure Linux system enough, or does more need to be done?
When installing GUFW (if one goes that route), does the repository need to be updated (via sudo apt) before installation via the terminaL? More generally, does sudo apt- get updates need to be run each and every time a command is run through the terminal, or is it ok to pass on updating if you have ran sudo apt, say yesterday?
Thanks for all the help.