Keep ubuntu up-to-date

How to keep Ubuntu up-to-date (requires an internet-connection)

Graphical way

1. Go to "System"-->"Administration"-->"Update manager"
2. Click "Check"
3. If there are updates to install, click "Install updates"
4. Close the "update manager"

Terminal way

type this a terminal:

sudo apt-get update

and then:

sudo apt-get upgrade