First interview is usually with an HR Mgr over the phone. This interview is basically for HR to decide whether they should have you proceed to the next step int he process and is basic in nature. Topics discussed include work experience, current job requirements, etc. Usually lasts 15 minutes at the most.
Second interview will be with the Manager of the department where you are applying, followed by the Director of said deptartment. (i.e. Guest Service Manager --> Director of Guest Services/Front Office) These interviews are the most formal and most important. They want to see if you are qualified for the position and if you will perform well. They are analyzing not only the answers to your questions, but how you respond, the tone of voice you use (do you speak with confidence and conviction?), and your body language. If you are honest (truly honest) and genuine, then it only comes down to experience up againt other candidates.
Final interviews will be with the General Manager and Director of HR (they both have final say and veto-power). Once you've made it this far, it's just a formality. You should still act as professional as possible, but at this level, the company just wants to make sure you are a good fit for the culture.