Rclone is mainly for keeping files in sync/transferring files between multiple storage providers, for example copying a file to GDrive/Dropbox when such file is added to S3 or locally. It supports multiple storage providers.

Borg is for backups. It doesn't support any storage provider.

One can use both of them jointly, creating borg backups and saving them on GDrive for example.

You can use rclone sync with `--backup-dir` which is a flag stolen straight from rsync so you can keep old versions of your data.

You do something like this

    rclone sync /path/to/source remote:destination/current --backup-dir remote:destination/$(date -I)

Which will give you a complete current backup and sparse historical backups.

So for historical backups you can have deduplication, but rclone doesn't support deduplication within the sync though, so if you have two identical files within a directory, rclone will upload them both.

I don't know Borg very well but you can use it to back up to an rclone mount. I did look into making a borg server for rclone so it could speak borg protocol directly over ssh. It wouldn't be too hard, but the protocol isn't documented so it would mean reverse engineering the python code.