# The Principle of BR

__*BR Principle*__
__*BR Features*__

+ Hot backup
+ Physical backup
+ Incremental Backup & recover
+ Data object backup & recover
+ remote backup
+ Backup data encryption

![right](./student-guide/diagram/BRPIBackupStore_aa_001_20220618.png)
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BR issues backup or recover operation commands to individual TiKV nodes. After TiKV receives the command, it performs the corresponding backup or recover operation. In one backup or recover, each TiKV node will have a corresponding backup path. The backup file generated during TiKV backup will be saved in this path, and the corresponding backup file will be read from this path during recover.

Cluster snapshot backup: TiDB cluster snapshot data only contains all the latest data of the cluster at a physical point in time that satisfies transaction consistency. BR supports backing up cluster snapshot data. Refer to Backing Up TiDB Cluster Snapshots.

Cluster incremental backup: TiDB cluster incremental data contains the difference between the start and end snapshots of a certain time period. Incremental data is smaller than in full volume data, and is suitable for use with snapshot backups to reduce the amount of data backed up. Refer to Backing up TiDB cluster incremental data.

Backup only specified library tables: BR supports filtering out unnecessary backup data on the basis of snapshot backups and incremental data backups, helping users to back implement only business-critical data. Please refer to Backing up the data of the specified database table of the TiDB cluster.

Backup data encryption: BR supports encryption of backup data on the backup side or on the storage service side when backing up to Amazon S3. Users can choose one of them according to their own circumstances. Refer to Backup Data Encryption for usage.

Restoring a cluster snapshot backup: You can restore a snapshot backup on an empty cluster to recover the cluster to the latest state of the cluster at the time of the snapshot backup. Please refer to recover a cluster snapshot backup.

Restoring cluster incremental backups: You can recover incremental backup data for a certain period of time. Refer to Backing up TiDB cluster incremental data.

recover a specified library table from a backup: You can recover only the partial data of the specified library/table in the backup data. This feature filters out unwanted data during the recover process, and can be used to recover data from a specified library/table on a TiDB cluster. To use, refer to recover the data of the specified library table in Restoring Backup Data.