Configuration of programs continue even after they have been uninstalled

Question

I’m new to Linux and noticed that some program settings continue even after they have been uninstalled. I’ll explain. For example: I installed Cairo Dock. So to uninstall I used the command:

sudo apt-get remove cairo-dock

Then I used the remote:

sudo apt-get autoremove

So far so good, but I ended up installing this dock again and when I clicked on open, it remained with all the programs that there were before I uninstalled it. Would there be any other command to uninstall completely? Another thing that I found strange was that after uninstalling the Cairo Dock, I installed another dock and to my surprise, when uninstalling also this other dock, it remained active because I forgot to leave it.

How do I get the programs to be fully uninstalled?

Settings for my Linux:

DISTRIB_ID=Linuxmint DISTRIB_RELEASE=18.2 DISTRIB_CODENAME=Sonya DISTRIB_DESCRIPTION="Linux Mint 18.2 Sonya" NAME="Linux Mint" VERSION="18.2 (Sonya)"

Answer 1

Try the following:

sudo apt-get purge cairo-dock

The command purge does the same thing as remove, but besides removing the installed packages of the mentioned program, it also removes all the settings left by it.