Android reference for App Resources: https://developer.android.com/guide/topics/resources/index.html
From Android Web Site
All user interface elements in an Android app are built using View
and ViewGroup
objects. A View
is an object that draws something on the screen that the user can interact with. A ViewGroup
is an object that holds other View
(and ViewGroup
) objects in order to define the layout of the interface.
Android provides a collection of both View
and ViewGroup
subclasses that offer you common input controls (such as buttons and text fields) and various layout models (such as a linear or relative layout)