Question: System Settings can be run from the launcher (pinned by default), the Dash, or the power cog. But what command would I enter in a terminal window if I want to run it from there?

Answer: 
For [Ubuntu Mate](https://ubuntu-mate.org/) the command is `mate-control-center`.
In Crouton, you must run anything that would require a password from the terminal, such as update manager, software center, synaptic, etc. So, to get to system settings you would enter in the terminal:

```
gnome-control-center

```

That will bring up the system settings GUI.

To check for updates, or if the update manager appears in the Unity Launcher, run it from the terminal, not by clicking on it:

```
sudo update-manager

```

The same applies to synaptic, the software center, etc. Anything which requires a password, must be run from the terminal in Crouton with a `sudo`.