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A Store Update is an update for which a newer version of the code (thus the app) has to be submitted.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.