Can you download software for iPhone 4S on an iphone 4?

I wanted to get the new ios 7 for my iphone 4 but I like the one for the iPhone 4S better. Is it possible that I can use that software instead or are they two completely different software?

What? IOS 7 is iOS 7! They are the same! Will the iPhone run iOS 7? If so it's the same!

IOS 7 the same on all devices, except some features aren't enabled on older devices because the devices can't handle them. Also, iOS 7 doesn't come out to the public until the fall, but you can install it early if you register your device's UDID on a site like http://www.instantudid.com/.It's $5, and then you can try it out before everyone else.