cannot understand the following code in android
<pre><code>    ss.setSpan(new URLSpan("tel:1234556"), 13, 17,
            Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
    tv.setText(ss);
    tv.setMovementMethod(LinkMovementMethod.getInstance());
</code></pre>

<p>what does the linkMovementMethod do?
what is the URLSpan class and what is the use of it? what does the string tel:123456 mean?
Is tel a keyword? </p>

<p>Need answer asap
thank you in advance.</p>
