If you create the instance with Backup feature enabled (check prices and creation menu), the backup is created automatically in the internal schedule. Most often this is weekly, in the time of low cloud load.
If the instance supports on-demand backups, you can initiate instant backup with the Control Panel option.
Linux-like OS Backup Consistency
Due to lack of any consistency external backup platform, Linux VPS backups are crash-consistent only. This means that the backup quality is approximately correspond to situation of unplanned reboot of the VPS server. Usually it is completely fine because most of modern software and filesystems use internal measures to guarantee consistency in case of the OS crash.
If you need application-consistent Linux OS backup, you should implement a custom backup solution from inside, such as legacy UNIX-like "dump" approach, or a mysqldump to a safe place, or whatever.
Microsoft Windows Backup Consistency
The Backup platform is Microsoft Data Protection Manager 2012 R2 (DPM). It creates application-consistent backups for a large set of Microsoft software such as Operation system itself, SQL Server, SharePoint Server, Exchange Server, via Hyper-V Shadow Copy backup integration.
This means that before the backup, DPM talks to the software inside your Windows OS to get it prepared for the snapshot. Database app can flush caches properly and get a solid backup with no subject to additional crash-recovery risks.