Vignette.

To use the vignette tool you first have to select a new layer and then the marquee tool and pick whether you would like the tool to create a rectangular or circular effect.

Click select, then inverse, then select again and modify:feather.
pick the amount of pixels you would like to be feathered then command and backspace to then put the effect in place.

This is the original image that I have used.

This is the final product, I chose for the fade to be black rather than white because the colours in this image are dark.