You enter your estimated arrival time, have a few options for room requests, and enter your credit card info for room charges, and then you receive a text on your check in day when your room is ready. It is supposed to save time and allow you to bypass the front desk. I prefer to check in in person. The one time I used online check in, I never received a text and had to go to the front desk anyway so there was no benefit. I also prefer to be there in person, that way if I'm unhappy with the room I receive I can ask to be reassigned at that time.