Before an application can call HealthVault, two things must happen: 1. The application configuration must be added to HealthVault. 2. A user must allow the application to access his/her health data. The application configuration specifies how the application will interact with HealthVault (i.e. which methods it will call, which data types it needs access to, etc.). It also provides information specificially for the user (i.e. a description about what the application does, the application logo, etc.). This information will be shown to the user during application authorization.