“The ability to store data locally on the mobile device is a critical function for mobile applications that are required to maintain essential information across application-executions or the lifetime of the application. As a developer, you constantly need to store information such as user preferences or application configurations. You must also decide if you need to tap internal or external storage, depending on characteristics, such as access visibility, or if you need to handle more complex, structured types of data. Follow along in this article to learn about Android data storage APIs, specifically the preferences, SQLite, and the internal and external memory APIs.”
See my article Understanding Android local data store APIs (IBM developerWorks) which introduces the different local data store APIs on Android.