I got this from the free shop: and I had the option to add it to my wardrobe or to redeem it. I'm not sure what the difference is.

If you redeem it you can use it in the hair salon (change colour, add highlights, etc.), but you will not be able to remove it and sell it again. If you put it in your wardrobe you can use it like any other wig or clothing item in there, and remove it whenever you want, but you can't change it's colour.

Thank you!