What is the purpose of anti-rollback protection in IoT devices

Question

I’ve seen anti-rollback protection mentioned in IoT firmware updates, but I’m not exactly sure why it’s needed.

• Can an attacker downgrade firmware to an older, vulnerable version to exploit known flaws?
• How does anti-rollback protection prevent firmware downgrades?
• Are there standard cryptographic techniques used to enforce anti-rollback?

Would love to understand the importance of anti-rollback security in IoT firmware management.