How to change Apple account back to Apple ID

Practically speaking there is no difference. Apple just changed how they referred to things. Previously it wasn't clear if people meant their account or just the user name part of it. "I forgot my Apple ID so I can't sign into my Apple ID." Now --> "I forgot my Apple ID so I can't sign into my Apple Account." Much clearer.

It takes a while for people to adjust. If you see me referring to Apple ID I mean just the email or telephone number part of account information. Also, it is possible with search engines to find posts dating from up to 20 years ago so you may be looking at old threads.

You have long (at least in the 20+ years I have been on this forum) been able to change the email address used with an account. Change your Apple Account primary email address - Apple Support There have been some issues with re-using an old email address, though Apple has relaxed a bit on that:

Change your Apple Account primary email address - Apple Support

- If you remove an email address that isn’t an iCloud email address from your Apple Account, it can’t be associated with another Apple Account for 30 days for security reasons. After removing an email address from your account, notify anyone who might contact you on Messages, FaceTime, or other Apple apps using that Apple Account email address. After 30 days, another user might be able to associate that email address with an Apple Account for Messages, FaceTime, and more.

If you can’t change your Apple Account primary email address

- If you try to change your Apple Account to an @icloud.com email address that was created within the last 30 days, you will be asked to try again later.

- If you see a message that the email address you want to use isn’t available or is already in use, check that you or a family member aren’t already using that email address with a different Apple Account. If a family member is using that email address, remove it from their account, then try to use it.

From: How to delete your Apple Account - Apple Support

“Can I use the primary email address for my deleted Apple Account to create a new Apple Account or with another existing Apple Account?

No, once your Apple Account is deleted, you can’t use the email address that you used with it to create a new Apple Account for as long as Apple retains the one-way hash of the email address. For third-party (non-Apple) domain accounts, the one-way hash is deleted after six years. For other accounts, this is retained according to Apple's retention policy, which is reviewed regularly. In addition, you can’t use that email address with another existing Apple Account except as a rescue email. Also, if your primary Apple Account email address is with a Custom Email Domain, it can never be reused to create an Apple Account after your Apple Account is deleted, even if the domain ownership changes.”

I am not clear as to what you are asking.

Apple re-named "Apple ID" to "Apple Account" a while ago. They are the same thing (except some of us now use the term "Apple ID" to refer to the email address or telephone number part of your account information alone).