How do I apply package updates to my Ubuntu system?

Ubuntu Linux provides simple but easy to use GUI and CLI tools to apply package updates to your operating systems. Before installing an update, ensure all previously-released errata relevant to the laptop or desktop/server have been applied.

Applying package updates on Ubuntu Linux using GUI

To access updates when using Ubuntu, launch the graphical update tool through Activities > Show Applications > All > Software & Update, or from the command line via the following command:
update-manager
It will check and apply all updates. It will also prompt for your password when needed.

How do I apply package updates to my Ubuntu system using command-line?

For a command line interface, use the following apt command to update the Ubuntu Linux operating system package database:
sudo apt update
Now apply all updates from the Internet:
sudo apt upgrade
You may need to reboot the computer when new Linux kernel installed. Try the reboot command or shutdown command to reboot Linux system:
sudo reboot
## OR ##
sudo shutdown -r now
To install a specific package, such as nginx, run the following command:
sudo apt install nginx
We use the same command to update a specific package, such as apache2, use the following command:
sudo apt install apache2
To find more information about the command line options available for apt, use the following man command:
man apt

Summing up

apt is a command-line package manager and provides commands for searching and managing, and querying information about packages. It provides the same functionality as the specialized APT tools, like apt-get command and apt-cache command, but enables options more suitable for interactive use by default. Here is list of most used commands and the syntax is:
apt {command}
Where {command} can be:

• list – list packages based on package names
• search – search in package descriptions
• show – show package details
• install – install packages
• reinstall – reinstall packages
• remove – remove packages
• autoremove – Remove automatically all unused packages
• update – update list of available packages
• upgrade – upgrade the system by installing/upgrading packages
• full-upgrade – upgrade the system by removing/installing/upgrading packages
• edit-sources – edit the source information file
• satisfy – satisfy dependency strings