Now, before we actually get into the ins and outs of managing packages, there's actually two completely different types of packages available to you, and you should understand the differences between them. As of the time this book has gone to press, we're at a kind of crossroads regarding the way in which software is managed in Linux.
Traditionally, each distribution has their own package format, and their own utilities to manage them. Nowadays, there's a push to adopt a single package format that each distribution can install. Contenders for this single package format include Flatpak, AppImage, and Snap packages. Specific to Ubuntu, it utilizes Debian packages (with package names ending in .deb) as the main package format, which Ubuntu inherits from the Debian distribution (Ubuntu is forked from Debian...