What backup type backs up only the data that has changed since the last full backup?

What backup type backs up only the data that has changed since the last full backup?

• A. Differential Backup
• B. DNS Poisoning
• C. DDoS
• D. Dig

Answer: (A)

This tests how backups track changes relative to a baseline. A differential backup backs up only the data that has changed since the last full backup. After you perform a full backup, each subsequent differential copies everything that has changed since that full backup, so the amount of data grows as more changes occur until the next full backup resets the baseline. This makes recovery straightforward: you restore the last full backup and then apply the most recent differential. The other options aren’t backup types. DNS poisoning refers to manipulating DNS records for malicious purposes, DDoS is a denial-of-service attack, and Dig is a network utility used for querying DNS records. They relate to security or troubleshooting, not to how backups capture data.

This tests how backups track changes relative to a baseline. A differential backup backs up only the data that has changed since the last full backup. After you perform a full backup, each subsequent differential copies everything that has changed since that full backup, so the amount of data grows as more changes occur until the next full backup resets the baseline. This makes recovery straightforward: you restore the last full backup and then apply the most recent differential.

The other options aren’t backup types. DNS poisoning refers to manipulating DNS records for malicious purposes, DDoS is a denial-of-service attack, and Dig is a network utility used for querying DNS records. They relate to security or troubleshooting, not to how backups capture data.