Photoshop combining color with black and white - A non-destructive method

This is a small Photoshop tutorial on how you can make a part of a picture black and white and still part of it remain colored. Unlike a lot of other techniques that can be used to create this effect, THIS technique is NON-DESTRUCTIVE to your image, it allows you to make changes to an image without overwriting the original image data which will remain available in case you want to revert back to it. Because nondestructive editing doesn't remove data from an image, the image quality doesn't degrade when you make edits. I am sorry for the lousy audio, when I made this tutorial all I has was a separate handheld microphone that I had to hold while doing the photoshopping, it made for lousy audio but, you can still understand what I am saying.