If I have a iPhone 4 how do I know if it is a 4s?

If I have a iPhone 4 how do I know if it is a 4s?

The only obvious difference would be Siri. Go to settings then general. If its a 4s you will see Siri there. If its not there then you only have a 4.

Well the "s" in 4s stands for- Siri
Siri is the intelligent personal assistant that helps you get things done just by asking, It is voice operated. So to find out if you have the 4s you simply need to find out if you have Siri, To do that you just press down on the home button for a few seconds until you see it pop up on the bottom of your screen and will make a little noise.

The button

The 4s has Siri and an improved camera. That's about it…

Yes, You can check it by your self simply Go to settings then general- If you will see Siri there that means it is 4s. If its not there that means you have iphone 4.

Siri (or lack thereof). No Siri, its an iPhone 4. Easiest & most obvious giveaway.

http://www.everymac.com/systems/apple/iphone/iphone-faq/differences-between-iphone-4s-iphone-4.html