For security reasons, iPhone OS restricts the application (including its settings and data) to a unique location on the file system. This limitation is part of the security feature known as sandbox applications. A sandbox is a collection of fine-grained controls that limit application access to files, preferences, network resources, hardware, etc. On iPhone OS, the application and its data are in a safe place, which no other application can access. When the application is installed, the system calculates a unique opaque identifier for the application. Using the application root directory and this identifier, the system creates the path to the application home directory. Thus, the home application directory can be depicted as having the following structure:
/ApplicationRoot/ApplicationID/
During installation, the system creates a home application directory and several key subdirectories, configures the application sandbox, and copies the application package to the home directory. Using a unique location for each application and its data simplifies backup and restore operations, application updates, and deletion. Learn more about the directories of specific applications created for each application, as well as application updates and backup and restore operations.
see application sandbox
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