When updates are available for your Ubuntu Server machine, the following lines "xxx packages can be updated" and "XX updates are security updates" will be displayed.

Bash

xxx packages can be updated
xx updates are security updates

Note : If you are running Ubuntu Desktop, you will have an icon like this will be displayed.

1. Update the system via the terminal
2. Update system by the GUI

1. Update the system via the terminal

To begin, make an update of the list of packages (to then retrieve the latest versions of each program) by typing the following command :

Bash

apt-get update

Then download all the new versions of each program to update just by typing this :

Bash

apt-get upgrade

If the message "The system must be rebooted" appears, then type the command "reboot" to restart the Ubuntu machine.

Bash

reboot

2. Update system by the GUI

Click the "Update Manager" icon, then click "Install updates".
You must have root privileges to perform these updates.

It's possible that Ubuntu will ask you to restart your computer to finish installing updates.