Disaster recovery involves preparing technology infrastructure to continue operations after a disruption. It grew from protecting mainframes in the 1970s to today's emphasis on always-available IT systems critical to business. Disaster recovery planning considers both natural events like floods or earthquakes and human-caused issues. While requiring time and money, disaster recovery is important because data loss or downtime can significantly harm a business through lost customers and reputation. Effective disaster recovery identifies backup sites, data protection, training drills, and key personnel coverage to minimize business impacts from disasters.