Hahah heey girl! I'm here to help ! Beauty guru ova here ! Well you don't have to use it..but a lot of girls do to protect your hair. YOu can go to a walmart, walgreens, target, ulta, anywhere you go...they'll prob. have it. YOu spray this into you hair , then brush through ur hair, and then straighten ur hair..and it straightens ur hair without damamging it !
so, honestly my hair is straight, but looks wayy (haha) better if I use straighten, and my advice is use "defrizzer" (kerastase has a good one) in all your hair, when it's still wet, before the straighten or hairdryer... x) This will protect your hair and gets it shaining ;) that's what I do, wish it helps you :)