Tutorial: Ubuntu MATE 18.04 Getting Updates
The Software Updater available from the Ubuntu MATE Welcome app or from the menus is the update manager for Ubuntu MATE. Ubuntu MATE periodically checks to see if new software and security updates are available for your computer. The updates are for Ubuntu MATE, all of its components, and all of your installed applications. This ensures that you have the latest updates and protection for all of your computer's software as soon as it's available, not just once a month like other operating systems.