The color range tool in the panel and in Photoshop is a method for creating masks based on specific colours in your images. This is different to the Colour Masks in the panel, where colour masks look for a colour in all pixels, the color range tool is looking for colour matches.
When you select the “Color Range” button another pop-up window will appear. Using this pop-up window you’ll be able to start making selections in your image based on exact colours. At the top of the page there is a “Fuzziness” slider, the lower the number the more selective Photoshop will be in trying to match the colours you choose, the higher the number the broad Photoshop will be in selecting colours. The color range tool defaults to 40, I recommend starting here and if it’s selecting to much, lower it, and if it’s not selecting enough, increase it.
On the right of the screen you will see 3 eye-droppers, an eye dropper on it’s own, one with a “+” symbol and one with a “-” symbol. Choose the one with no symbol to make your initial selection, then if you want to add to your selection, select the “+” eye dropper and if you want to subtract from your selection choose the “-” eye-droppers.
Once you have completed your selection, press OK on the pop-up window and your selection will then be loaded for you to use with other tools in the panel such as adjustment layers and dodging and burning.
The video below will show how to use the Color Range tool in more detail.