1. Loaders

　　loaders make it easy to asynchronously load data in an activity or fragment. Loaders have these characteristics:

　　　　<1>They are available to every Activity and Fragment.

　　　　<2>They provide asynchronous loading of data

　　　　<3>They monitor the source of their data and deliver new results when the content changes

　　　　<4>They automatically reconnect to the last loader‘s cursor when being recreated after a configuration change. Thus, they don‘t need to

　　　　　　re-query their data

2.App Components-Activities/Loadres