Backup strategies — definitions: An incremental backup is best described as which of the following?

Introduction / Context:
Backup schemes determine what data is copied and when. Understanding full, differential, and incremental backups is essential for designing reliable recovery plans while managing storage and time costs.

Given Data / Assumptions:

• Files have metadata indicating last modification time and backup status.
• A full backup captures everything; follow-up backups may capture only changes.
• Goal is to minimize backup duration and storage while preserving recoverability.

Concept / Approach:

An incremental backup copies only files changed since the most recent backup of any kind (often the last incremental or full). This reduces data volume and time but may require a longer restore sequence: latest full + all subsequent incrementals in order.

Step-by-Step Solution:

Verification / Alternative check:

Backup software documentation consistently describes incrementals as capturing changes since the previous backup, contrasting with differential (since last full) and full (everything).

Why Other Options Are Wrong:

• Should be done each month: Schedule is policy-dependent, not definitional.
• Uses more tapes: Incrementals typically use less storage per run; restore may need more sets.
• Saves all files: That is a full backup, not incremental.
• None of the above: Incorrect because option D is correct.

Common Pitfalls:

Confusing incremental with differential; underestimating restore complexity when many incremental sets exist.

Final Answer:

saves only files that have recently changed