Understanding the various UI widgets available in Android definitely empowers you to make various design choices about how specific functions and behaviors in your application should present themselves, but there is more to activity design than picking a radio button or TextView. Layouts are Android’s declarative mechanism that arms you with control over the complete on-screen landscape for your application.
Conceptually, a layout acts as both a container of the widgets you wish to use in an application or activity and the blueprint and scaffolding for how all of the widgets ...
