The document discusses the 3-2-1 backup rule for avoiding data loss. The rule recommends having 3 copies of your data stored on different media, with 2 backup copies and 1 copy stored offsite. Following this rule helps protect against data loss by providing redundancy and keeping copies separate in case of hardware failure, human error, or natural disaster affecting your on-site storage. The document provides examples of data loss situations and stresses the importance of validating your recovery strategy, documenting recovery steps, and testing backups.