How it works
Dynamic DNS updates a DNS record when the address of an internet connection changes. A router or update client reports the current address to the DNS service, allowing a stable name to keep pointing at the connection. This solves naming, not the separate question of whether a remote device can reach the intended service.
Important differences and limits
A correct name cannot bypass carrier-grade NAT, firewall rules or missing port mappings. DNS caching may also delay how quickly another device sees an address change. Publishing an address does not authenticate visitors or encrypt the service, and the update credentials must be protected just like other administrative access.
A useful practical check
Check the connection’s addressing arrangement before configuring remote access. Compare the DNS record with the actual public address and test from a genuinely external connection. Keep the update client active and secure. Prefer an appropriately configured VPN or supported remote-access method rather than exposing management interfaces directly simply because a hostname is available.
An example in practice
A hostname may resolve correctly from inside the home while an outside connection still fails. Test from another network to establish external reachability. Conversely, a stale DNS record can point to an old address even when the current internet connection itself is working normally.