Updates are include in every active app subscription. There are two kinds of app updates:
A Content Update as the name indicates, is an update to the content of the app. New texts, images, design and even added building blocks can usually be sent through a content update. Content updates are instantly sent to the app and do not require the app to be re-submitted to the stores.
A Store Update is an update for which a newer version of the code (thus the app) has to be submitted. Also changes made on the Publish page of the app will trigger a store update. Store updates for Google may take up to 1 business day, whereas a store update for Apple can take up to 8-10 business days.
When you navigate to the Publish page of your app and hit the "Update your app" button. The wizard will open and tell you whether your app can be updated through a content- or store update.