Understanding different backup types is crucial for effective data protection strategies. Here's a breakdown of the relevant backup methods:
* Full Backup: Captures all data, regardless of previous backups.
* Differential Backup: Backs up data that has changed since the last full backup.
* Incremental Backup: Backs up data that has changed since the last backup, whether it was full or incremental.
* Snapshot: Captures the state of a system at a specific point in time.
A Differential Backup starts with a full backup. Subsequent differential backups save copies of all files that have been modified since that full backup. This means each differential backup includes all changes made since the last full backup, leading to larger backup sizes over time but faster restoration, as only the last full backup and the latest differential backup are needed.
In contrast, an Incremental Backup also begins with a full backup, but each subsequent backup only includes data that has changed since the most recent backup (whether full or incremental). This approach results in smaller backup sizes and quicker backup processes. However, restoration can be slower and more complex, as it requires the last full backup and all subsequent incremental backups to fully restore data.
Therefore, the correct answer is A. Differential, as it specifically refers to backing up files that have changed since the last full backup.
References:
* CompTIA Server+ Certification Exam Objectives (SK0-005): Backup Methods
* CompTIA Server+ (SK0-005) Study Guide: Chapter on Security and Disaster Recovery