First a general phone screen, then a prep interview over Facetime or Skype, then finally a one-on-one on-campus interview. You will be asked to particpate in hypothetical scenarios that deal with customers having various problems with their iOS devices. They care more about your level of empathy for customers and your ability to communicate with them, rather than technical knowledge about Apple's products, as all of that would be covered in training once they decide to hire you.