Differences between the iphone 4 and 5?

I can get an iphone 4 for free, but i'm wondering if it's a better deal to get the iphone 5 for $200. What are the differences?

The iPhone 5 screen is bigger. And the charger port is different. That's pretty much it.

I think the difference is that is runs faster, can hold more apps, and is bigger in length.

What you get in the 5 you don't get in the 4. Siri, LTE, larger screen, faster processor, more RAM, less weight.

A iPhone 4 has only 512mb of RAM and a 800Mhz processor, you also won't have Siri either…
iPhone 5 has 1GB of RAM, a 1.3GHz processor, and a Retina display. LTE is also included, and a different charging/sync cable. What does that all mean? More RAM means more you can do at once (Leave Apps in background run, without much of a slow down), a faster processor for better graphics and games run smoother, and a Retina display to (of course) display movies, pictures, and apps more beautifully. LTE (When you have a good signal) is supposedly faster than Wi-Fi, and the different cable is digital to make syncing faster (not necessarily make charging faster).It also has a longer battery life.

The iPhone 5 has a modestly larger screen, but because the housing is thinner and lighter than the iPhone 4 and iPhone 4S it doesn't really "feel" bigger overall. The aluminum iPhone 5 housing also generally is more durable than the glass iPhone 4/4S housing, although it is more subject to nicks and scratches, so much so that some have been scratched before even leaving the factory. Most notably, the iPhone 5 also is significantly faster than then iPhone 4 and iPhone 4S, has faster 4G/LTE networking support (with the exception of the China only model), and has better cameras, too.

The iPhone 5 is taller and has a different charging port. Not really much difference.