What's the difference between disaster recovery and backup?

According to the definition, backup means that users make one or more copies of important data (or original important data information) generated by the application system to enhance the security of data. Therefore, backup and disaster recovery focus on different objects. Backup focuses on the security of relational data, while disaster recovery focuses on the security of business applications. We can call backup "data protection" and disaster recovery "business application protection". At most, backup shows that data is copied by using tape drives or tape libraries through backup software, and some users use disks and optical disks as storage media; Disaster tolerance is manifested in connecting two sites through a high availability scheme.

Backup and disaster recovery are two extremely important parts in the storage field, and they are closely related. First of all, both backup and disaster recovery have data protection, and backup is mostly in the form of tape, which has low performance and low cost; Disaster recovery uses disks to protect data, which can be online at any time, with high performance and high cost. Secondly, backup is a foundation in the storage field, and a complete disaster recovery scheme must include backup; At the same time, backup is an effective supplement to the disaster recovery scheme, because the data in the disaster recovery scheme is always online, so the storage may be completely destroyed. Backup provides an extra line of defense, and even if online data is lost, it can be recovered from the backup data.