I have a Iphone 4s, is there anything Iphone 5 can do that not available for 4s user?

I mean, is there any exclusive feature that the Iphone 5 can do, and that other older Iphone can't do, should I upgrade to Iphone 5?

Nope apple just wants you to think you need a new one but you don't

As far as i know the actual features are the same, there's no major additions, but it's got significantly better hardware, better processes etc. If you have a 4s stick with that, it isn't worth upgrading, only reason i got the iphone 5 is because i've been stuck with a 3gs for too long!

Nope just a bigger screen apple just wants more money

Yes there's. You can't get the A6 chip lighting speed. But I'd personally recommend to stick to iPhone 4S. You can do everything what iPhone 5 does.