Here are a few situations when users can encounter empty states within an application:

Error state, such as getting a no internet connection.

No content in a particular category of items. Such as no incoming emails, albums, or connections.

User action is required. The app cannot show the data because the user didn’t do something. For example, the user didn’t connect a payment method in the app. This type of empty state is especially common during the onboarding and initial use stages when the user didn’t fully configure the app.

The tips in the article are good, so recommended reading when you want to learn more about empty states.