Configuration is divided into two categories: static and dynamic.
Configuration that is intended to be modified only at application development, assembly, or deployment time is considered to be static. This kind of configuration can only be modified before the application becomes operational. Changing any of the static configuration parameters fundamentally changes the application and, therefore, would require its redeployment. New code or resources can be added as a result of changing static configuration. Consequently, the application would have to be rebuilt, retested, and redeployed.
Configuration that controls the behavior of the application while operational is considered to be dynamic. The application observes and reacts to changes in its dynamic configuration without having to be rebuilt, retested or redeployed. Changes in dynamic configuration do not result in application resources having to be added, changed, or removed.