To answer your first question, just look at the Description section of the Get-AppxPackage cmdlet.
The Get-AppxPackage cmdlet gets a list of the app packages that are installed in a user profile.
The answer to your second question depends on what you're trying to do. If you want to remove all types of the package, then use the -PackageTypeFilter as you did in your example. If you want to remove just the packages that aren't usable on your machine's architecture (e.g., X64, X86, ARM), then make that selection from among the results of the packages using all package types. "Bundles" usually contain everything, though: specific architecture and resources.; so, you can't remove part a bundle.