Native mobile apps are downloaded to a device, built for that specific platform using languages like Objective-C or Java, and can access device features. Mobile web apps live on the web, are accessible via browser, and are built using HTML/CSS/JS. Native apps are best for utilizing device capabilities like gaming or sensors, while mobile web apps allow for lower costs, rapid updates across devices, and accessibility without downloads. The document provides examples of when each type of app is most suitable.