The App Store
Four packaging systems in one place, with the source of every application stated plainly rather than buried. The same application often exists in more than one of them, and which one you pick has real consequences.
The four sources
| Source | What it is | Reviewed by |
|---|---|---|
| Repositories | Arch's own packages, plus ours. Native, smallest, best integrated with the system. | Arch package maintainers |
| Flatpak | Sandboxed applications from Flathub, carrying their own runtime. Newer versions, larger downloads. | Flathub, with per-application sandbox permissions |
| Snap | Canonical's format. Present because some software ships here and nowhere else. | Canonical, with automatic review for most publishers |
| AUR | Build scripts written by other users. Off by default. See The AUR. | Nobody. That is the whole point of the page about it. |
Where an application exists in more than one source, the store matches them up and shows you the choice rather than picking silently. A Flatpak of the same program is usually newer and always larger; the repository version is usually better integrated. Neither is right in general.
Ordering
The default preference is repositories first, then Flatpak, then Snap, then the AUR. That order runs from "reviewed by a distribution and integrated with your system" to "arbitrary code from a stranger", which is the order most people would choose if the information were in front of them.
AppImages
An AppImage is a single executable file. The store can install one you have already downloaded, or fetch one and integrate it so it appears in your application menu like anything else.
The order of operations is deliberate: download, verify, then make executable. An AppImage is an executable fetched over the network, and marking it runnable before knowing it arrived intact is the one step never worth skipping.
Many AppImages carry no update information at all. When that is true, the store says so at install time rather than leaving you with a program that silently never updates again.
Keeping things current
Repository packages, Flatpaks and Snaps are all updated by the nightly update run, so keeping current is one thing rather than three. AUR packages are the exception and are covered in The AUR.
What the store will not do quietly
Removals go through the same guard as everything else. If a package the system depends on is about to be removed, the check inside pacman stops it no matter which application asked. See Terminal Assist.