i am new in android and i am developing application . I have read in the developers.google.com that if i want the application screen compatible then my icons should be in ldpi , mdpi , hdpi , xhdpi and android itself will pick is it like this ? if not then what i have to do making it screen compatible and also how to give the dynamic padding ? like right now my code is look like this 

```
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/splash_page"
 >

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" 
    android:layout_alignParentBottom="true"
    android:gravity="center_vertical">

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="600dp"
        android:layout_gravity="center_horizontal"
        android:background="@drawable/icon_login_btn"/>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:paddingTop="40dp"
        android:background="@drawable/icon_btn_register" />

</LinearLayout>

</RelativeLayout>

```

So , you see here i have give the margin top , but that work only on tablets not on large screen mobiles.