You apply and then you will receive and email of whether you made it to the next round or if you haven't. If you made it it will be HR asking when you can talk. You first talk to HR and they'll ask about your resume. If you pass that you'll then talk to the person you would be walking under, they will ask you more about your experience in the field. You'll then get a call from HR if you are accepted or an email saying you didn't.