Do you actually have to update your iPhone to IOS7?

I'm asking this question because I'm not to thrilled about tomorrow the date being of the IOS7 update on all iPhone's. I got my iPhone rather than an Android a year ago because it was basic, easy for me to use, and I've had an iPhone 3GS, 4, and 4S. So I was used to it. Recently almost 7 months ago, my mom got an iPhone 4S, and she uses the phone because it's easy for her to use: make calls, surf the internet, take pictures, and make texts. She loves the layout, and design. And isn't too tech-savy. So for her to update, means she'll have to get frustrated and used to a whole different software, and design! I feel the same way. Truthfully, I do not want to update to ios7. The only thing I'm afraid about is, when I charge/shut off my phone, or shut off my cell phone, and turn it on (on charge or without) and it automatically updates. I don't know if there's an option where I can shut that off. But, back when I has ios5 I shut my phone off, turn it on. And it went through the whole update process without me confirming or knowing about it! I don't want that happening to me, or my mom with iOs7, so is there a way I can shut that off or not? I have an iPhone5, and my mother an iPhone 4S. My dad has a Samsung Galaxy S2, so there's no worry with that. And my brother has an iPhone 4 (not sure if ios7 is coming on the 4), but if so. I know he'll update and want to!

Well if you don't want to, then don't, but you'd just be limiting yourself.

No you don't have to. I usually wait a few weeks after it comes out, then I upgrade, there are alot of good features in iOS 7 so I really want this release (call blocking features, airdrop, free radio, etc)