What's it called when you show images according to their category with a button?

What is it called when you can show images according to their category, or show all by clicking on a button?

Probably best if I give an example. If you take a look at this page, not the first section, but the sections after. On the example it is called filtering, but trying to find that on Code Canyon is virtually impossible, as you end up with all the image filtering effects.

http://www.davidbo.dreamhosters.com/?page_id=2

Thanks.