Disaster Recovery and Backup
What data can you afford to lose?
What would happen to your company if your server / computer crashed and all your data was lost?
Would you be able to stay in business and recover?
For a home user, what if you could not recover your tax documentation and / or family pictures?
The only way for sure to know your backups are working is to try restoring your files.
Backup Strategy 3-2-1
3 copies of everything, in at least 2 different physical locations, 1 of those locations being offsite away from your computer.