"implements" keyword in java?
<p>I am new to android development, I have gone through some code and found the following line of code :</p>

<pre><code>class Preview extends SurfaceView implements SurfaceHolder.Callback {
}
</code></pre>

<p>Can someone explains or give me a hint to what is really happening here especialy on implements <code>SurfaceHolder.Callback</code>?</p>

<p>thanks</p>
