What's the difference between the iPhone 4 & 4s?

I'm getting a new phone in the next couple of months and I was told to get the 4 because it would be cheaper and the only real difference is Siri (which could be jailbroken) from the 4s. So then why make a phone if there aren't much differences that could be put into the other one? O.o

My dad has 4s and i have 4, he used to have 4 but upgraded and he said there was no point as siri is the only difference and no one uses it

IPhone 4s is much faster than iPhone 4 since iPhone 4s has a dual core cortex A9 however iPhone 4 uses a single core cortex A8, and also iPhone 4s has an 8mp iSight camera, but the 4 5mp, and the iPhone 4s has siri and more features of iOS especially 6 more than the features of 4, 4 is now kinda old go for 4s or 5:)

IPhone 4
- A4 Chip (Processor/Speed)
- -5 Megapixel Camera
- 720p HD video recording
- No panorama picture mode

IPhone 4S
- A5 Chip (Processor/Speed)
- Siri (Virtual Assistant)
- 8 Megapixel Camera
- 1080p HD Video Recording
- Video Stabilization

Hi.Look up the phones on cnet or phonescoop. Then you can compare specifications and features of each phone side by side