An Android Intent is an abstract description of an operation to be performed. It can be used with startActivity to launch an Activity, broadcastIntent to send it to any interested BroadcastReceiver components, and startService(Intent) or bindService(Intent, ServiceConnection, int) to communicate with a background Service.The intent itself, an Intent object, is a passive data structure holding an abstract description of an operation to be performed.
Android provides many ways of storing data of an application. One of this way is called Shared Preferences. Shared Preferences allow you to save and retrieve data in the form of key,value pair.

In order to use shared preferences, you have to call a method getSharedPreferences() that returns a SharedPreference instance pointing to the file that contains the values of preferences.

- Notification messages to the user from an Android enabled device can be displayed using Intents.

- There are two types of Intents - Explicit Intent, Implicit Intent.

Implicit Intent:

- In case of Implicit Intent, an intent is just declared. 

- It is for the platform to find an activity that can respond to it.

- Since the target component is not declared, it is used for activating components of other applications.

Explicit Intent

- Explicit intent specifies the particular activity that should respond to the intent. 

- They are used for application internal messages.