I'm sorry if this is a stupid question, but I was searching for a file in Dash when I saw 'Remmina Remote Desktop Client'. Judging by the icon, it doesn't look like default software. I'm the only one who uses this pc so I want to ask is RRDC automatically installed or did I install it by accident?
It is installed by default, though I'm not sure what you judged from the icon.
$ apt-cache depends ubuntu-desktop | grep remmina Recommends: remmina
It is the default remote desktop/VNC client on Ubuntu.