The mobile phone received an appleid code message.

What you want to ask is why the mobile phone receives the appleid code information? Account security verification, prevention of unauthorized access, account change notification and two-factor authentication.

1, account security verification: Apple sends a code message to verify the identity of the account holder and ensure that only legitimate users can access and use the account.

2. Prevent unauthorized access: By sending code information, Apple can prevent unauthorized people from trying to log in or change AppleID settings. This is an effective measure to protect account security.

3. Account change notification: When the AppleID information changes, such as changing the password or adding new security settings, Apple will send a code message to inform you.

4. Double authentication: Enable double authentication. Every time you log in or perform sensitive operations, you need to provide additional authentication steps. This includes receiving code information from Apple.