How is CSS pixel movement same in every monitor resolution : <p>Lets says I have the following CSS:</p>

<pre><code>#div-1 {
position:relative;
top:20px;
left:-40px;
}
</code></pre>

<p>If load it on Monitor A and drag my browser to monitor B with a different resolution, HTML div will be at the same spot, although pixel numbers are different in monitors. How does that work?</p>
