There are two types of backups you can download.
Download Last Backup
The database and media storage (local media only) are backed up to a remote location daily.
When choosing to download the last backup, you will download the data as it was at the time of the backup. You can download the Mastodon Secret Hashes and PostgreSQL Database and Media Files (without remote cache).
Generate a Backup from Live Data
If you want to generate a backup from live data, your Mastodon server needs to stop, and this will allow you to download all the data as it is at that moment.
You can also download Mastodon Secret Hashes and PostgreSQL Database and Media Files (with or without remote cache).
This is the option you should choose if you want to Migrate your Mastodon server from Masto.host to another hosting solution.
Limits
You can download up to 4 backups from the Last Backup and 4 from the Live Data every 30 days.
Currently, backups need to be downloaded manually, and there is no option to backup to the remote storage you provide (it's planned but not yet available, sorry).
About Backups
The general recommendation for data safety is to have 3 copies of your data. All Masto.host hosting plans include two copies, the live data and an automated daily backup to a remote data center.
To keep the hosting plans as affordable as possible, Masto.host does not make the third recommended copy. For a higher level of data safety, you should regularly download and keep a copy of the backup safe.
Tech details
Please read: Access To Backups