Editing Dynamic DNS (section)

=== Domain Name System ===
DNS is based on a [[distributed database]] that takes some time to update globally. When DNS was first introduced, the database was small and could be easily maintained by hand. As the system grew this task became difficult for any one site to handle, and a new management structure was introduced to spread out the updates among many [[domain name registrar]]s. Registrars today offer end-user updating to their account information, typically using a web-based form, and the registrar then pushes out update information to other DNS servers.

Due to the distributed nature of the domain name systems and its registrars, updates to the global DNS may take hours to distribute. Thus DNS is only suitable for services that do not change their IP address very often, as is the case for most large services like Wikipedia. Smaller services, however, are generally much more likely to move from host to host over shorter periods of time. Servers being run on certain types of [[Internet service provider]], [[cable modem]]s in particular, are likely to change their IP address over very short periods of time, on the order of days or hours. DDNS is a system that addresses the problem of rapid updates.