title: Use of intent filter in explicit intent
body: <p>I am going one activity to another using an explicit Intent and I declare it in the manifest file.</p>
  
  <pre><code>&lt;activity
      android:name=".Activity2"
      android:label="Activity 2"&gt;
  
      &lt;intent-filter
          action android:name="com.tr.ACTIVITY2" 
          category android:name=”android.intent.category.DEFAULT"&gt;
      &lt;/intent-filter&gt;
  &lt;/activity&gt;
  </code></pre>
  
  <p>It works fine but one book uses <code>intent-filter</code> for this and I am confused about when we use intent filter.</p>