An android component is simply a piece of code that has a well
defined life cycle e.g. Activity, Receiver, Service etc.
The core building blocks or fundamental components of android are
activities, views, intents, services, content providers, fragments and
AndroidManifest.xml.
Activity
An activity is a class that represents a single screen. It is like a Frame or window.
View
A view is the UI element such as button, label, text field etc.
Anything that you see is a view.
Intent
Intent is used to invoke components. It is mainly used to:
Start the service
1. Launch an activity
2. Display a web page
3. Display a list of contacts
4. Broadcast a message
5. Dial a phone call etc.
Service
Service is a background process that can run for a long time.
There are two types of services local and remote. Local service is accessed from
within the application whereas remote service is accessed remotely from
other applications running on the same device.
Content Provider
Content Providers are used to share data between the applications.
Fragment
Fragments are like parts of activity. An activity can display one or
more fragments on the screen at the same time.
AndroidManifest.xml
It contains informations about activities, content providers, permissions etc.
Android Virtual Device (AVD)
It is used to test the android application without the need for mobile or tablet etc.
It can be created in different configurations to emulate different types of real devices
