Backups are automatically-created disk images of Droplets. Enabling backups for Droplets enables system-level backups at weekly intervals, which provides a way to revert to an older state or create new Droplets.
Enabling weekly backups for a Droplet adds 20% to the cost of the Droplet.
Now in early availability, Droplets in NYC1, NYC3, SFO3, and AMS3 support daily backups. Enabling daily backups for a Droplet adds 30% to the cost of the Droplet.