An app installed from the App Store or Google Play that runs directly on iOS or Android with full access to device features.
A native app is built to run on the phone's operating system and is distributed through app stores. It can fully use the camera, location, notifications, biometrics and Apple Pay. Some modern technologies let you build iOS and Android apps from a single codebase.
Being in the store adds trust and easy access, and notifications help bring customers back. On the other hand, every update goes through store review, and there are requirements and developer account fees. Fanann builds real iOS and Android apps from the same conversation. Practical tip: do not start with a native app just because it looks professional. Go native when usage is frequent or you truly need device features, and prepare a privacy policy and support page before submitting to the stores.