Application properties have the largest scope of all properties. Application properties are useful when you want to share the same value for an existing module property across multiple processes in an application or between an application module and a shared module. You can either promote an existing module property to the application level or create a new application property.
Refer to Promoting Module Properties for Visibility at the Application Level for steps on how to promote a module property and Creating an Application Property for steps on how to create a new application property.
You can use application profiles to store multiple values and switch profiles at deployment time. Refer to Creating an Application with Multiple Profiles for details on creating profiles.