Editing technique question

Ok, I feel a little lame asking this, but been away for a little while, and discovered a neat new (to me) technique I would like to try out. I tried googling several different topics, and came up empty handed as I don't really know what exactly it's called. Here is a link to a photographer's website (hope it's ok to post it). On the cover of their site they have an example of what I am looking to do. Basically it's 2 photos blended together in a silhouette!

http://davinaplusdanie​l.com/weddings/

In old terms it's probably called a double exposure. In new terms it's probably done with layer masks and layer blend modes in Photoshop.

Google "How to create a clipping mask in Photoshop" and you will find numerous tutorials you can follow to achieve this effect.

Thanks all, those were definitely not the correct key words I was using to search......Did a quick search and found a couple tutorials, I will spend more time with it after tomorrow's wedding.....thanks again.....Jake

There are several ways to do this. If you're shooting Nikon (like your linked photographer), you may even be able to do it in-camera, since some Nikons permit multi-exposure.

You can also sometimes do this with a single shot using a reflection off a window although the conditions need to be just right and getting sufficient DOF can be tricky.

And, has been mentioned, there are multiple ways in Photoshop to do it.

Jasper James was really hot in photography forums a while back for this type of photography. I recommend you check out his work:
http://www.jasperjames​.co.uk/project/people-and-places-2/