Well, you answered it right there - it has a larger screen. However, a larger screen is far more useful for general use and browsing around the home. I have both, and pretty much have the same apps on both. My iPhone is for use when I'm out and about, and my iPad is for use at home on the sofa. I didn't think I'd see much benefit from owning both too, but now I do, I can clearly see they perform very distinct functions. Gaming is often better on the iPad, but not always, and neither is a substitute for the other.