Sometimes an update message is only referring to your settings, not a software update.
Other updates you can disable from updating automatically. That is a choice you can make of your own free will. If you don't want it then turn it off (see below).
Some changes it asks you at the time if you wish to update. You may have to be carefully interpret the wording in some requests that Apple makes because it is not always clear what they are asking.
From: Update your iPhone or iPad - Apple Support
Customize Automatic [iOS] Updates
Turn on automatic updates
1. Go to Settings > General > Software Update.
2. Tap Automatic Updates, then turn on Download iOS Updates.
3. Turn on Install iOS Updates. Your device will automatically update to the latest version of iOS or iPadOS. Some updates might need to be installed manually.