I would like to update installed packages for security on Ubuntu 18.04 LTS server. How can I update my Ubuntu 18.4 system using apt command/apt-get command?

Introduction: Keeping your system, kernel and installed application is an essential sysadmin task. An updated Ubuntu 18.04 LTS system means fewer security issues and increased system stability. Ubuntu Linux is pretty user-friendly when it comes to applying updates and patches. This page shows how to update Ubuntu Linux system using the apt-get command/apt command or the GUI tools for desktop installation.

Ubuntu 18.04 update installed packages for security

The procedure to install updates on Ubuntu:

1. Open the terminal app.
2. For remote server log in using the ssh command: ssh user@server-name-here.
3. Issue the command sudo apt update to refresh package database
4. Install/apply updates by running sudo apt upgrade command.
5. Reboot the system if kernel was updated by typing sudo reboot command.

Let us see all steps in details.

Ubuntu Linux 18.04 LTS: Updating your system using GUI

The GUI method is easy which works great if you are using Ubuntu on a Laptop or Desktop. Press the Super key (Windows key) and type the following in search box:
update manager

Wait for some time as “Software Updater” need to refresh the database. Once repo refreshed you will see the following box if any software updates available for your Ubuntu Linux 18.04 LTS:

Click on the “Install Now” button. You must provide your password in order to install updated software on Ubuntu Linux:

Finally you will see the following dialog box installing software:

Once installed you may be promoted to reboot the Ubuntu Linux system:

How to install updates via apt command line for Ubuntu 18.04

Open up a terminal application or log in using ssh. Run the following command to upgrade Ubuntu Linux system:
$ sudo apt update

Want to see all available package/software upgrades for Ubuntu? run:
$ apt list --upgradable

Finally, install updates via command line, run:
$ sudo apt upgrade
You need to enter your password when prompted. To accept updates press ‘y’ key (no quotes) and hit Enter key:

You must reboot system when Ubuntu Linux kernel gets updated:
$ sudo reboot

Conclusion

You learned how to install the software update for all installed packages using the GUI and CLI methods on Ubuntu Linux 18.04 LTS.