Types of backupThe Backup utility supports five methods of backing up data on your computer or network. 

Copy backup

A copy backup copies all the files you select, but does not mark each file as having been backed up (in other words, the archive attribute is not cleared). Copying is useful if you want to back up files between normal and incremental backups because copying does not affect these other backup operations. 

Daily backup

A daily backup copies all the files that you select that have been modified on the day the daily backup is performed. The backed-up files are not marked as having been backed up (in other words, the archive attribute is not cleared). 

Differential backup

A differential backup copies files that have been created or changed since the last normal or incremental backup. It does not mark files as having been backed up (in other words, the archive attribute is not cleared). If you are performing a combination of normal and differential backups, restoring files and folders requires that you have the last normal as well as the last differential backup. 

Incremental backup

An incremental backup backs up only those files that have been created or changed since the last normal or incremental backup. It marks files as having been backed up (in other words, the archive attribute is cleared). If you use a combination of normal and incremental backups, you will need to have the last normal backup set as well as all incremental backup sets to restore your data. 

Normal backup

A normal backup copies all the files you select and marks each file as having been backed up (in other words, the archive attribute is cleared). With normal backups, you only need the most recent copy of the backup file or tape to restore all of the files. You usually perform a normal backup the first time you create a backup set. 

Backing up your data using a combination of normal backups and incremental backups requires the least amount of storage space and is the quickest backup method. However, recovering files can be time-consuming and difficult because the backup set might be stored on several disks or tapes.

Backing up your data using a combination of normal backups and differential backups is more time-consuming, especially if your data changes frequently, but it is easier to restore the data because the backup set is usually stored on only a few disks or tapes. 

For more information, see To set the backup type.