Your Apple ID is the account you use for everything you do with Apple—including using the App Store, Apple TV app, Apple Book Store, iCloud, Messages, and more.
Your Apple ID consists of an email address and a password. Sign in with the same Apple ID to use any Apple service, on any device—whether it’s your computer, iOS device, iPadOS device, or Apple Watch. See the Apple Support article Sign in with your Apple ID.
Note: In some locations, you can use a phone number instead of an email address as your Apple ID. See the Apple Support article Use your mobile phone number as your Apple ID.