Context on Android

 Here we are going to explain what's exactly is a Context class in Android and what is it used for?

As the name suggests, it's the context of the current state of the application/object. It lets newly-created objects understand what has been going on. Typically you call it to get information regarding another part of your program (activity and package/application).

You can get the context by invoking getApplicationContext(), getContext(), getBaseContext() or this (when in a class that extends from Context, such as the Application, Activity, Service and IntentService classes).
Typical uses of context:

• Creating new objects : Creating new views, adapters, listeners:

 TextView tv = new TextView(getContext());
 ListAdapter adapter = new SimpleCursorAdapter(getApplicationContext(), ...);

• Accessing standard common resources: Services like LAYOUT_INFLATER_SERVICE, SharedPreferences:

 context.getSystemService(LAYOUT_INFLATER_SERVICE)
 getApplicationContext().getSharedPreferences(*name*, *mode*);

• Accessing components implicitly: Regarding content providers, broadcasts, intent

 getApplicationContext().getContentResolver().query(uri, ...);


You can read more from the Developer Site, From there you can understand it more clearly.