An Apple ID is a UserAccount that has a valid email address, protected by a password set by the user that is a case-sensitive alphanumeric string of at least eight characters. In March 2013, Apple ID launched an optional two-step verification security feature for authentication. When enabled, a second verification step is required when using the Apple ID under certain conditions, such as a web login, or making a Store purchase from a new device. The feature uses the Find My iPhone service to send a four-digit pin code to a trusted device associated with the Apple ID when the second verification step is required for authentication. Users can have different Apple IDs. Users can change their passwords or personal information. Apple also allows users to change the name of an Apple ID but users must contact Apple customer service to make such a change.[from Wikipedia].