best way to have page background only on home page

A site in the portfolio area does exactly what I want to do, www.ca-pyrenees-gascogne.fr
The home page has a full width background with navigation elements on top of it, but when you navigate to other pages the navigation remains but the image is not there. I have watched tutorials and read some topics, but I am still unclear how to do this. Thank you.

Hi
you can use Slideshow CK as slideshow in the background of a wrapper, using the "container background" option of the module. Then you can assign the module to the home page only
CEd

PS : I'm currently in holidays