I'm trying to secure my internet browsing. I just reinstalled Xubuntu 14.04 and GUFW firewall. I have 8 UDP ports open. I don't understand why. The software I currently have open are Firefox, GUFW, Mousepad, Ubuntu Software Center, Software Updater and Terminal. Would any of these correspond with the open software? When I installed GUFW its introduction said it installs with no open ports as well as Ubuntu. The applications related to the open ports are avahi-daemon, dhclient, and cups-browsed. I'd rather close them if they're not needed.
Instructions on closing them via GUFW or Terminal would be appreciated as I am a novice.
I can attach a screen print if needed.