Content Provider ContentProvider and content parser ContentResolver,
I personally think it is a good introduction: content provider ContentProvider and content parser ContentResolver
The role of ContentProvider in android is to share data externally, that is, you can share the data in the application to other applications through ContentProvider for access. Other applications can use ContentProvider to add, delete, modify, and query data in your application. For example, (the contact/information has its own provider) the principle of ContentProvider is to expose its own interfaces to other applications according to certain rules to access the data of its own applications (in fact, it is to customize the addition, deletion, modification, and Query Interfaces and expose them out, allows other applications to access their own data ). ContentResolver accesses the data of the content provider according to certain rules (in fact, it calls the custom interface of the content provider to operate on its data ).