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Bounding div with position: relative. Whole bunch of nested elements with position: absolute.

All of those plus icons, and their associated text are the nested (position: absolute) items.

Then they use javascript to hide all the text and display them on hover.
 
Start off easy, then start to make it more complicated.

Code:
<div style="position: relative; background: green; width: 500px; height: 400px;">
<div style="position: absolute; top: 100px; left: 50px; width: 10px; height: 10px; background: blue;">
 
</div>
<div style="position: absolute; top: 200px; left: 450px; width: 10px; height: 10px; background: blue;">
 
</div>
</div><!-- green div -->

This will make a green box with two small blue boxes inside of it positioned absolutely.

If you don't understand that conceptually, you just need an HTML book.
 
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