Data security refers to the protection of data from unauthorized access, use, change, disclosure and destruction and includes network security, physical security, and file security.
Data storage refers to holding your data files in a secure location that you can readily and easily access. Data backup, in contrast, refers to saving additional copies of your data in a separate physical or virtual locations from data files in storage.
Security needs to be considered for all copies of your data, including your working data set, backup copies and archived copies.
Keeping backups of your data. There is a real risk of losing data through hard drive failure or accidental deletion.