Touch is only part of what makes the iOS devices different from OS X. The other half is direct manipulation — you touch the very thing you want to manipulate. O

Touch is only part of what makes the iOS devices different from OS X. The other half is direct manipulation — you touch the very thing you want to manipulate. On OS X, there is a pointer between you and the things you want to manipulate. That pointer gives you increased accuracy, speed, etc. But it also means your hands and fingers don't block your view of the screen. All things put together you end up with a drastically different way of interacting with your computer. People who aren't UI or UX designers may gloss over these things. But Apple is obsessive about this stuff.