In a world of technology, data is the most valuable resource. One of such meta datas is your CCTV security surveillance recordings. You can protect this data with backup. There are three basic types of backups; full, incremental and differential.

Full backup

A full backup is a full copy of the entire data set. Full backups provide the best protection; however, due to its time consuming nature and large storage requirement, most organizations use this type of backup on a periodic basis. This leaves the organization susceptible to data loss between two backups.

Incremental backup

Incremental backups were introduced as a way of decreasing the amount of time that it takes to do a full backup. This backup only creates a backup of the data that has changed since the previous backup.

For example, if you created a full backup on Friday, and used incremental backups for the rest of the next 6 days, then Saturday's backup would only contain the data that has changed since Friday. Sunday's backup would only contain the data that has changed since Saturday. Monday's backup would only contain the data that has changed since Sunday and so on until you take a fresh full backup on the following Friday.

A major disadvantage of incremental backups is that while they are save time when creating backup, they can be very time-consuming when restoring data. In the above example, if you want to restore the backup from Tuesday, you would have to first restore Friday's full backup, then Saturday’s incremental backup, then Sunday’s incremental backup, then Monday’s incremental backup and finally Tuesday’s incremental backup. If any of these backups are damaged or missing, then you will unable to perform a full restoration.

Differential backup

A differential backup is similar to an incremental backup. They both start with a full backup, and any subsequent backups only contain the data that has changed. The difference between the two is that an incremental backup only includes the data that has changed since the last previous backup, whereas a differential backup contains all of the data that has changed since the last full backup.

For example, if you want to create a full backup on Friday and differential backups for the rest of the week. Saturday's backup would contain all of the data that has changed since Friday, and it would thus be identical to an incremental backup at this point. On Sunday, however, the differential backup would backup any data that has changed since Friday, when the last full backup was made. Consequently, a differential backup on Thursday would backup any data that has changed since Friday’s full backup.