CompTIA Cloud+ Practice Test

What type of backup identifies only modified data since the last backup operation?

1. Incremental Backup

2. Full Backup

3. Differential Backup

4. Mirror Backup

The correct answer is: Differential Backup

The type of backup that identifies only modified data since the last backup operation is known as a Differential Backup. This method keeps track of changes made after the most recent full backup and ensures that all modifications are included in the backup without duplicating previous data. When performing a differential backup, the backup process looks at the last full backup and saves only the data that has changed since that point. For instance, if a full backup was taken on a Sunday and a differential backup was taken on both Monday and Tuesday, the Tuesday backup would include all changes from Sunday up to Tuesday, whereas the Monday backup would only include changes from Sunday to Monday. As a result, if a restoration is needed, the user would only need the last full backup and the most recent differential backup, making this method efficient in terms of storage and faster recovery times. In contrast, other backup types serve different purposes. A Full Backup captures all data, regardless of whether it has changed or not, requiring more storage. An Incremental Backup captures only the data that has changed since the last backup of any type, which can make recovery more complex as multiple backup sets might need to be restored. Lastly, a Mirror Backup creates an exact replica of the source data and does not track changes