what is an apple password

See the article https://appleid.apple.com/faq/#!&page=faq

The Apple ID password is created https://support.apple.com/en-gb/guide/mac-help/mchlp1088/10.14/mac/10.14

To sign in with the Apple ID account page https://support.apple.com/en-us/HT203993

Both Apple ID mail address and password is required , it depends the account holder created an account with secondary authentication or two factor authentication to enter more essential credentials to sign in .

In simple words Apple ID is a mail address created with some web mail services like gmail , yahoo ..initially and a tough password is created along with it to sync the device like iPhone / Mac with apple servers .

An Apple ID has two components, an email address and a password. For example the email address might be name@iCloud.com. And, the password can be what you want, but as a practical matter it should be a strong password. This read tells you where you can use your Apple.ID https://support.apple.com/en-us/HT202659 To create an Apple ID, go here: https://support.apple.com/en-us/HT204316