First off, Dynamic DNS, also known as DDNS, is a service that will instantly update your IP address (the A or AAAA record) if the host (device) changes it.
When your IP address’s lease ends, your ISP (Internet service provider) can change it automatically.
You can use DDNS to ensure that the device will remain accessible if you utilize it as a server. Otherwise, you won’t be able to reach the new IP address or determine it from a distance.
Without Dynamic DNS, if you are operating a monitoring server with a camera at home and you have been viewing the video from a distance, the connection will break the instant the ISP changes the IP address, and you won’t be able to see anything.
Domain Name System (DNS) is a naming database system. It is locating and translating domain names into IP addresses. Imagine it is like a directory or even like a mobile’s contacts list. Each one of the names corresponds with numbers, and they are accurately matched. DNS directory is spread worldwide. This system operates daily. It helps to explore and reach millions of domain names every day. Without Domain Name System, we would have to remember each site’s IP address to visit it. This sounds nearly impossible, considering how many sites are out there.