A mobile app is downloaded and installed on the phone, and is in fact software, while a mobile website is just an ordinary website, but with it's lay-out optimized for mobile phones, and likewise divices
[TABLE] [TR] [TD="class: votecell"] [/TD] [TD="class: answercell"] A web app is accessed via Safari and requires no install. You are just going to a website that has a special stylesheet for the iPhone. A native app runs code on the device and is installable through the app store. You have access to all the UI elements the iPhone uses and can do things like 3D which are impossible in Mobile Safari. You need a mac to make a native app, but can make web apps with any platform of your choosing. [/TD] [/TR] [/TABLE]