How do you record your iPhone screen (without using a different device)?

I have tried using it but it isn't working. I have a iPhone 5c which I'm pretty sure is up to date. I'm not even certain if it works on iPhone 5c but please help me.

IOS 11 will bring native screen recording. Unfortunately the 5c (& 5) aren't getting that update.

As of now there's no way to do that, except for using a computer with QuickTime to do so.