A quota is a limit on the amount of isolated storage that can be used. The quota includes bytes of file space as well as the overhead associated with the directory and other information in the store.Isolated storage uses permission quotas, which are storage limits that are set using IsolatedStoragePermission objects. Security policy, which can be modified using the caspol utility, determines which permissions are granted to code. Code that has been granted IsolatedStoragePermission is restricted to using no more than the specified quota. However, because code can bypass permission quotas by presenting different identities, permission quotas serve as guidelines for how code should behave rather than as firm limits on code behavior.