Android ADB Backup

Android backups (.ab) are backups made by Android Debug Bridge (ADB). They are the preferred way of backing up an unrooted stock android device. (Manufacturers and/or carriers may provide their own backup tools). They can be encrypted or unencrypted. They can be created via ADB backup and restored via ADB restore.

Flags

-all Backups all compatible apps
(package id) Backs up the stated package(s) if compatible.
-system backups system apps if -all or a system package Id is stated.
-nosystem does not back up system data.
-apk Backs up the .apk of the app(s)
-noapk does not back up apk files
-obb Backs up .obb (app extention) files
-shared Backs up all shared storage (/storage/emulated/0/), including SD cards and USB OTGs, so it is recommended to eject and disconnect any external storage unless you want to back up that.
-noshared does not back up shared storage.

Discontinuation

Android backups are being discontinued and fully replaced by Google Drive backups. Google drive backups cannot be downloaded, and there is a 25 MB per-app limit. You need a network sniffer to log upload traffic to capture these.