Easy and Fast, the XML Layout :

XML layouts might seem simple at first, but it’s going to get complicated really quickly.

Laying Out :
Most XML screens will be wrapped in a layout object. Layout objects come in many different flavors. 

LinearLayout : 
All elements are arranged in a descending column from top to bottom or left to right.

Each element can have gravity and weight properties that denote how they dynamically

grow and shrink to fill space. Elements arrange themselves in a row or column notation

based on the android:orientation parameter.