There is a huge difference between native apps and web apps. Both of them are entirely different and developed with different technologies. Native apps are developed especially for a platform and are compatible solely with that single platform or mobile operating system. Native apps may or may not require an internet connection depending upon the type of application and its features.
Web applications run directly on the browser and are compatible with all the platforms and mobile operating systems. The only pre-requisite for web apps is a stable mobile internet connection or wi-fi connection for the app to work. With a single codebase, web apps are easy to maintain and update regularly.