
The main differences lie in their ability to be installed on devices and work offline, access to advanced APIs that allow interaction with device features such as camera, gyroscope and address book, and the existance of a solid developer ecosystem - including a Marketplace for distribution of free and paid apps.

and can be accessed using a web browser. They are built using standard open web technologies - HTML, CSS, JavaScript, etc.

Firefox OS apps are essentially no different to standard websites or web apps.
