Content Providers
Content providers provide data share mechanism among
applications. The data that be shared could in the file system,
a SQLite database, or any other persistent storage location an
application can access. A content provider is implemented as
a subclass of Content provider, it defines the data format it
supported and provides a set of method to enable other
applications to query or modify the data. But an application
does not call these methods immediately, instead, it call
these methods by an object named Content Resolver.
Content Resolver can communicate with every Content
Provider. Content Resolver cooperated with Content
Provider to manger IPC (inter process communication) while
sharing data.