Backup is an important way to safeguard your data, not just against ransomware but against physical damage that may occur to the storage devices and computers in an organization. There should be backup of data both for an individual and an organization. It is important not only to guard against ransomware but to protect you against data corruption by any other means such as hard disk damage or anything else that can be thought of. Data can be backed up on cloud storage.

Windows has a backup option. You can find the option by going to Control Panel| System and Security | Backup and Restore:

There is also other software for backup. Clonezilla is a piece of freeware that can be used for backing up disks. Google Drive is an example of a cloud service to store data. In the case of an organization, they store their data in a version control system. Tortoise SVN and Git are pieces of software that can be used to store your data.