What's the difference between iphone 4 and 5?

I was thinking of buying an iphone but I wanted to know the difference between them. Please tell me: o!

The 3 biggest changes between the 4 and the 5 are:

1. New lightning connector.

Getting the 4 would make you even less compatible with future devices since Apple will be ditching the old 30-pin connector.

2. The speed difference. The speed difference between the 4 and 4s wasn't bad, but the difference between the 4S and 5 is definitely noticeable. The internet, apps, boot time and overall performance across the 5 is amazingly quick! I'm still pleasantly surprised at times even though I've had my iPhone 5 for about a month now.

3. Screen size. Movies and youtube videos look ABSOLUTELY GORGEOUS on the iPhone 5. Because youtube uses a 16:9 ratio, and the iPhone 5 uses that as well, you get the entire screen for your videos and it is a significant step up. The speakers are also much louder and clearer. I find myself watching youtube much more often on my iPhone 5 now, because of the speed and clarity.

I'd say get the iPhone 5 because it is a very impressive phone.