Enterprise Storage: Four Main “Markets”

Online storage large disk array solutions, minimizing access time to the data, and maximizing reliability;
Backup off-line storage for data protection, with a smaller price per byte than online storage, but at a cost of higher average access time; often uses sequential access storage, such as tape libraries;
Archiving technically similar to backup, but its purpose is long-term retention, management, and discovery of fixed-content data to meet regulatory compliance, litigation protection, and storage cost optimization objectives;
Disaster recovery solutions used to protect the data from localized disasters, usually being a vital part of broader business continuity plan