Dynamic DNS (DDNS) is a service that automatically updates a domain name when your public IP address changes. It allows you to access devices and services remotely without needing a static IP.
Most ISPs assign dynamic IP addresses that change periodically. When the IP changes, direct access using the old IP breaks. DDNS solves this by keeping a hostname updated with the current IP.
A device, router, or script detects IP changes and notifies the DDNS provider. The provider updates DNS records instantly, ensuring uninterrupted access.
Free DDNS is suitable for basic needs and testing. Paid plans offer higher limits, better reliability, and advanced features.