Google Play

Google Play is an application by Google that can be found not only on Android phones but also on iPhone and Tabs( but in case of iPhone and Tabs you have to download it yourself). Since 2011,it had been launched it had also appeared on the Google.com webpage's above bar beside Gmail.

It is used for purchasing as well as downloading apps. 
For Example:
You want to download " Talking Tom 3" on your Android Tab or Phone.

1. Sign in with your Google ID and password.
2. Type "Talking Tom 3" in the Search box above.
3. A number of apps related to talking tom 3 will appear.
4. Choose any one of them.
5. Click on Install button.
6. IT   WILL  BE  INSTALLED!!!!!!!!!!!