title: Why do we specify namespace in android xml file?
body: <p>When we write a xml based layout in Android we use the string "xmlns:android="http://schemas.android.com/apk/res/android". </p>
  
  <p>From the books I read it says that this is a namespace, but why do we use this? The link doesn't even exist. So what is the use of this? </p>