Native apps are apps written in the native language of the platform of choice. It would be Java for Android and swift for IOS. Native apps can request lower level access to your system than a webapp.

Now, a webapp is a basically a website which can run like a native app with similar features and is full screen unlike a website. The language is javascript for the front-end and the backend(server) handles some communication. So, webapps can behave and act like native apps but they are not native and won’t have the same lower level access to your system. Think access to storage, accessibility services, settings, etc. Webapps can also be slower compared to native apps which is prominent in non-flagship smartphones.