Apple is introducing the Apple Account, a new unified login system that will replace the current Apple ID. This change will be implemented with the release of iOS 18, iPadOS 18, and macOS Sequoia in September
Apple says the reasoning for the name change is for consistent experience. Other than that, there are no changes to the functionalities whatsoever. Your Apple Account will be the same as the Apple ID. This means usernames, emails, passwords, and the like will remain unchanged.
In the future, if you update your device and spot Apple Account instead of Apple ID, there should be no concern on the matter. However, as noted by other tech media, the transition may cause a temporary confusion among Apple users, and so, may provide an opportunity for phishing scams to take advantage of the name change. We can’t confirm or even give examples of such situations. Just be mindful whenever you’ve been asked for your Apple Account, especially if it’s outside the device.