Android Example-Layouts in an Activity and Nesting of Layouts

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#1fecff"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="in.kantapp.example21.MainActivity">

    <TextView
        android:id="@+id/text"

        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Main Layout!" />


    <LinearLayout
        android:id="@+id/layout2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/text"
        android:background="#ffd544"
        android:orientation="vertical"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        android:elevation="1dp"
        tools:context="in.kantapp.example21.MainActivity">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Nested Layout" />
    </LinearLayout>
</RelativeLayout>

MainActivity.java

package in.kantapp.example21;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}