Push notification is a short alert the phone or browser can show while the person is doing something else. The app does not have to be open: a table is ready, a payment failed, tomorrow’s class moved. They allowed it once, and every extra ping after that spends the permission.
A native app and a cross-platform app, including one built with React Native, can both send them. A PWA can too, from the browser, with a narrower set of rules. Ask during onboarding, next to the first useful action, not on the splash screen.
Analytics should count who turns them off, not only who taps. A useful reminder can slow churn. A guilt ping speeds it up.
A real-life example of a push notification
A Midtown restaurant confirms a reservation from the app, twenty minutes ahead: the table on Peachtree is ready. One tap is a deep link straight to the booking. A second ping at 9 p.m. that says you are missed is how people mute the app and stop coming.
Send the alert that saves a visit, then stop. See push notifications in React Native and when reminders turn into guilt.